Good Omens/Fanfic Recs

What exactly do you find in a fandom of a book that makes the Apocalypse hilarious? Well, Slash Fic because Most Fanfic Writers Are Girls (including this troper who's responsible for 99% of all recs listed below). And some Continuation Fic (a Second Apocalypse is optional). But mostly slash.

Before you run away screaming, keep in mind that this article is part of an attempt to collect the 10% of fanfic that's worth dying for. That means that every fic on here was recced because of its high quality and in-character depictions. Which does include the slash.

These are recommendations made by Tropers for Good Omens fanfics, all of which have to be signed to stay on the page. Feel free to add a fanfic of your own to the list, but remember to use the template found here.

You can also add to the current recommendations if you want. Refrain from posting Conversation in the Main Page though; that goes in the discussion page.

Authors and Websites
irisbleufic's Good Omens Fanfiction @ LiveJournal
 * Recommended by Kelliannm
 * Comments: The best Aziraphale/Crowley slasher I know of, this author also writes superb gen fic (relating to the Them, Adam and Pepper in particular; however, she's written a few amazing Shadwell/Tracy and Shadwell-centric pieces, too). She also occasionally crosses GO with other fandoms (notably Hot Fuzz and Sherlock). Everyone is unbelievably in-character, but her Crowley-POV pieces shine brightest.

Daegaer's GO fanfics archived at LiveJournal
 * Recommended by Solandra
 * Notes: Most of Daegaer's works focus on Aziraphale and Crowley, and she gets their relationship down pat with the right doses of character quirkiness, snarkiness, and sweetness. She's also frighteningly talented at pulling off even the most crack-headed ideas. (For those of you who don't like slash, rest assured that Going Home and nearly all of Daegaer's other works don't make Aziraphale and Crowley's relationship any more suggestive than their canon one was, unless you really want to make an effort.)

H.J. Bender's GO fanfics
 * Recommended by Solandra
 * Pairing(s): Aziraphale/Crowley (sometimes gen, sometimes slash)
 * Notes: Saying these are funny is like saying that the original book has a slightly lighter approach to the Apocalypse. Even the shamelessly smutty fics are far more hilarious than Porn Without Plot have any right to be. As a bonus, Quantum Witch has illustrated some of Bender's fics for even more comedic goodness. (Be forewarned that while humor is the main staple of Bender's works, even the technically gen ones are packed with Ho Yay that barely stops short of actual slash.)

Fanfiction by Vulgarweed
 * Recommended by JAMoczo
 * Pairing(s): Aziraphale/Crowley with the occasional mixup
 * Notes: Do you like slash? Do you like some smut with your slash? Do you like your slash to be ridiculously well-written, fascinatingly historical, and droolingly hot? Then look no further! Vulgarweed is an amazing author who is still active in the fandom, and even better, she coordinates a lot with Quantum Witch, who (as she did for H.J. Bender) illustrated some fics too. Enthusiastically recommended!

The Gray Areas series by Macx
 * Recommended by Kereea
 * Status: The series itself seems discontinued, but all the stories are complete.
 * Pairings: Aziraphale/Crowley (established relationship),
 * Notes: Amazing. Takes the Not So Different vibes from the original to some interesting conclusions, with God and Satan meeting up for chats in several of the 23 stories, and God seems to be going for some ultimate end (which we never quite find out due to the unfinished status, but it's clear enough if you look at the subtext). It also looks at how different Aziraphale and Crowley are from normal angels and demons, including using Beelzebub and Michael as foils, shows how "demonic" and "divine" are similar but different (ex: angels can heal themselves and others, including demons, demons can heal themselves, but Beelzebub trying to heal someone else...doesn't go well). On the comedy side, Crowley (along with Azriaphale and Satan) gets a lot of snark in and is sometimes a bit of a Cosmic Plaything for everyone who isn't Aziraphale (he's most likely to be attacked without really doing anything, leading to him pointing out that 'Zira gets nowhere near as much abuse).

General Fics
''Stories focused on the family and the friendly relationships of the cast. Plot-focused stories or light day-in-the-life stories. Pretty much anything that isn't focused on slash romance.''

Should Old Acquaintance Be Forgot by Xylodemon
 * Recommended by Solandra
 * Summary: Gaiman and Pratchett actually wrote New Year's resolutions for Crowley and Aziraphale. This story takes Crowley's resolutions and expands each one into a story of its own.
 * Comments: Chock-full of Crowley-snarkiness, and that's all that's needed.

100 Things Crowley Would Do Before the World Ended by shewhoguards
 * Recommended by Hekateras
 * Summary: Other people plan 100 things to do before they die. Crowley planned 100 things before EVERYBODY died.
 * Comments: Exactly what it says on the tin, except not. What starts out as a humourous and light-hearted series of loosely connected drabbles quicky progresses into a poignant, thoughtful, touching plot involving trust, bad decisions and the Second Apocalypse. The writing is phenomenally in-character and follows very believably from where Aziraphale and Crowley left off in the book.

Of Wishes and Fishes by Googlebrat
 * Recommended by Solandra
 * Summary: When a not-too-bright dogfish swallows a wishing ring and causes mayhem with his careless wishes, a restless Horseperson sees a great opportunity, and only an angel and demon can restore things back to their natural order.
 * Comments: Has an entertainingly original plot guaranteed to leave you grinning.

When Summoning Please Watch The Wording by Ryuuza Kochou (Crossover with Supernatural)
 * Recommended by Echo Garrote
 * Summary: A capture, a ritual, and a small mistake in terms lets Sam and Dean become 'sacrifices' to another demon with yellow eyes. Things don't exactly end how you might expect them to.
 * Comments: Brilliantly written in a style that sounds just like Pratchett and Gaiman wrote it themselves. Everyone is in-character and it's absolutely hilarious.
 * Seconded by cg12345. Style is spot-on (for both 'Verses), and Aziraphale is shockingly badass at the climax. Beware the Nice Ones, indeed.

A Friend in Need by Pandarus
 * Recommended by Novium
 * Summary: Aziraphale gets an unexpected visit from a certain fallen angel from Supernatural.
 * Comments: This is a wonderful crossover. It is very funny, and so well captures the style of Good Omens that it's hard to remember that it wasn't written by Pratchett & Gaiman.

Da Capo Aria by Lady Oneiros
 * Recommended by Solandra
 * Summary: Aziraphale takes Death's place for a day upon God's request.
 * Comments: One of the rare Aziraphale-centric fics that does his character justice. Also has a non-Original Flavor prose (me pointing out that a fic's "great, but not in the style of canon" is just my Single-Issue Wonk, so don't let that deter you) that manages to be evocative and atmospheric without a whiff of Purple Prose or Pacing Problems, inspired characterizations of God, Lucifer, and Beelzebub, and themes about divinity and death that avoid Anviliciousness.

Be Ye Therefore Merciful by Ambular
 * Recommended by Solandra
 * Summary: Crowley is recklessly heroic and gets into severe trouble for it. Aziraphale will do anything to help him, even if it means defying Death.
 * Comments: Moving drama and Crowning Moments of Awesome for both characters make a gripping reading experience. (You can interpret this as pre-slash, but it's really about their canon relationship in general.)

Going Home by Daegaer
 * Recommended by Solandra
 * Summary: Aziraphale is recalled to Heaven, and Crowley isn't happy about it. After offing Aziraphale's Replacement Scrappy in a variety of amusing ways, he enacts a Heaven-contacting ritual that goes wrong in all the right ways.
 * Comments: I've already recommended Daegaer's fics in the Authors and Websites section, but this fic of hers deserves special mention as a work that pulls off the common "Aziraphale and/or Crowley are recalled by their superiors" plot brilliantly without descending into melodrama. In fact, you won't find any angst here, just light-hearted, humorous drama that's surprisingly poignant in showing just how much Aziraphale and Crowley mean to each other.

School Daze by Musegaarid
 * Recommended by feral
 * Summary: a Drabble involving Adam, Crowley, and "show and tell."
 * Comments: Crack Fic. Also the other stories by Musegaarid are recommended.

Daegaer's WWI series.
 * Recommended by feral
 * Summary: Hell sends Crowley to the trenches to snag some souls. But after a while of playing at being the good Captain sees him Becoming the Mask... made up of several short fics: War Is Hell, Brightness, No Man's Land, Gone for Soldiers, Monstrous Anger, Bright With His Splendour, Iconography, and At the Going Down of the Sun
 * Comments: It's an amazing, historically accurate period piece that really nails the characterizations of the canon characters.

Angels Online by Shati
 * Recommended by feral
 * Summary: Crowley teaches Aziraphale about the Internet in his own special way-lessons that come back to bite him in the arse...
 * Comments: Cue giggling into keyboard.

After All by AmberDiceless
 * Recommended by Lokis Scribe
 * Summary:Of course everyone knew there would be consequences, and that the world would have to end sometime. A story about What Happened After, with guest appearances by Him Below, the four Archangels and the Big Cahuna Himself.
 * Comments: Covers the "What do we do now?" aspect of the end of the book very well, from the point of view of Aziraphale and Crowley's superiors as well as them. Characterizes the relationship between Aziraphale and Crowley beautifully, and offers some really memorable characterizations of Lucifer, the Archangels, and God.

50 Accounts Of Hisses and Halos by saxgirl42
 * Recommended by Epitome O Random, Ice Wolfklaske
 * Summary: Fifty drabbles focusing on our favourite Angel and Demon, some WAFF with some dark ones.
 * Comments: The author keeps Aziraphale and Crowley in character all the way through, no matter what situation they're facing. There is a little slash but not enough to warrant putting it in the Shipping section. It's really... nice. You'll laugh, but personally, I ended in tears. Just a hand full of words and I got shot in the heart. Do try.

 The Viennese Job by A.A. Pessimal.
 * Recommended by Ag Prov
 * Summary: In turn of the century Austria, Crowley is ordered by Hell to befriend a struggling young artist. Whose mind had already been prepared for Hell by a hideous upbringing and the tender affections of Hastur and Ligur. Features Nostradamus and a cameo by Agnes Nutter.
 * Comments: In the opening years of the twentieth century, in a Europe that has been at peace for forty years, what storm could possibly disturb the idyll of the fin-de-siecle? Hell knows... a well-researched historical fanfic that garnered very good reviews.

Hastur Baiting by Laburnum Steelfang
 * Recommended by Ronfar
 * Summary: The Them encounter a slight problem when attempting to play Dungeons and Dragons. "What's the point of a scroll that just says 'HASTUR HASTUR HASTUR' over and over?"
 * Comments: Short and funny.

''[http://www.fanfiction.net/s/6990232/11/Agglomeration Ducks! and When Jim Met Seb]'' by Silver Pard
 * Recommended by SelinaCatz
 * Pairings: Sarah/John and John/Sherlock as Heterosexual Life Partners.
 * Summary: Sherlock Crossover featuring Sherlock, John and Sarah as ducks at St James's parks. Aziraphale takes Crowley to meet and name their ducklings.
 * Comments: It's about ducks, it shouldn't be this funny. It is anyway.

Shipping Fics
Stories focused on the romantic relationships between the cast.

Bad Grace by Quantum Witch (Contains an Aziraphale/Crowley slash subplot)
 * Recommended by Solandra, L Guardinal
 * Pairing(s): Newt/Anathema, Crowley/Aziraphale, Brian/Pepper, Adam/OC, and some other relationships between OCs
 * Summary: The end of the world has failed to happen, but things aren't going to settle back down anytime soon. Anathema's expecting, the Antichrist's about to enter puberty, an angel and demon find themselves irretrivably in a Romance Arc, the Seven Deadly Sins awaken, and the Second Coming of Christ draws nigh.
 * Comments: Like the original book, this Continuation Fic introduces several unique subplots, takes care to develop each of them with their own twists and surprises, and eventually draws all of them together at the climax to form a satisfying conclusion. Best of all, even when it takes the canon material into creative directions, it remains lovingly faithful to the established canon characters and relationships. The end result truly reads as a sequel to the original book.
 * Addendum by L Guardinal: (Most of) Quantum Witch's other works are quite good as well (though the vast majority, if not all of them, are Crowley/Aziraphale, sometimes quite explict, so read at your own risk). They can be found at The Good Omens Library.
 * feral: I especialy enjoyed Love Calls You By Your Name

A Precise and Accurate History of Monday, Eleven Years Later by Giddy Geek (Slash)
 * Recommended by Solandra
 * Pairing(s): Aziraphale/Crowley, Greasy Johnson/Pepper (yes, really)
 * Summary: Aziraphale and Crowley pay a visit to Adam eleven years after the Incident, presumably only to see how he's doing. But it's really more than that, and has to do with the New Arrangement formed during their trip to America.
 * Comments: Has the most perfect Original Flavor writing in the GO fandom, hands down. Crowley and Aziraphale are as entertaining as ever, Adam and the rest of Them have much-welcomed appearances, plenty of lines are giggle-inducing, and the progression of the main relationship over these eleven years is very much in-character and gives you a case of the warm fuzzies, especially at the closing lines. All without being sappy or losing that original-flavored witty edge.

Its Own Place by Unravel (Slash)
 * Recommended by Solandra, Ice Wolf Klaske (it pushed me over the edge to finally go read the book)
 * Pairing(s): Aziraphale/Crowley
 * Summary: Armageddon comes around again and Aziraphale and Crowley can't escape it this time.
 * Comments: The aftermath for Aziraphale and Crowley, for whom Earth felt more like home than Heaven or Hell ever did, is dealt with in a manner neither preachy or melodramatic but humorous and sneakily serious in a very canonesque way. Really, that's the best way to describe a fic with two opening quotes, one from Paradise Lost and one from a rock band, that can both be used to sum up the story. (Plus, the slash's well-integrated and the story arguably wouldn't be as emotionally powerful without it.)

Survivors' Guilt by irisbleufic
 * Recommended by Solandra
 * Pairing(s): Implied Aziraphale/Crowley at the end, easy to miss.
 * Summary: A series of vignettes about how significant historical events affect Aziraphale and Crowley over the years.
 * Comments: This story may not be as original-flavored as other fics like Eleven Years Later, but it's got a smooth, almost lyrical feel to it that captures the characters' raw emotions and developments without having to say them out loud.

For All the World, sequel to the above, also by irisbleufic (Slash)
 * Recommended by Solandra
 * Pairing(s): Aziraphale/Crowley
 * Summary: Crowley's still suffering from survivor guilt. Fortunately, Aziraphale is there to help him through it.
 * Comments: The focus this time is on Aziraphale and Crowley's relationship and personal lives, in deliberate contrast to the epic, history-changing events of Survivors' Guilt. Despite the different focus, it retains the same lyrical quality and emotional depth, making even the sexual references seem somehow clean and in-character instead of giving off that "dirty" vibe.

The Walls, the Wainscot, and the Mouse, also by irisbleufic
 * Recommended by 0 Wraith.
 * Pairing(s): Aziraphale/Crowley
 * Summary: Aziraphale and Crowley move into that cottage together in the South Downs. Cue people treating them like a couple, fawning over their pet-names for each other, and generally believing them to be life-partners. Eventually, they just decide that, really, they've technically been dating for six thousand years and might as well give it a go.
 * Comments: An adorable and fluffy story, unlike most of irisbleu's other fics. The characterization is especially good - Aziraphale and Crowley have an incredibly sweet relationship, and the OCs are brilliantly written (yes, even the mouse!)
 * Especially the mouse. Sweet and believable. Flame Feathers xx

Anything but Ordinary by Cimorene (Slash)
 * Recommended by Solandra
 * Pairing(s): Aziraphale/Crowley
 * Summary: A remix of Daegaer's AU fic Ordinary People that takes the original's basic concepts and ties them back to canon.
 * Comments: The Slice of Life events and gradually developing romance are done gracefully without ever losing sight of the fact that Crowley and Aziraphale are ethereal beings who, while being the most "ordinary" of their kind, are still anything but ordinary compared to humans.
 * The original AU fanfic must be recommended as well, as the author's depiction of what Aziraphale and Crowley would be like as humans makes for wonderfully interesting characters. This Troper would advise you to read the AU first and then the remix. Taken together, they're even better.

Once More With Feeling by Xylodemon (Implied slash, but only a small part of the plot)
 * Recommended by Solandra
 * Pairing(s): Aziraphale/Crowley, Newt/Anathema, implied Adam/Pepper and Adam/Harry
 * Summary: Hell hasn't given up after the Apocalypse That Wasn't, and formulates a new plan involving the wizarding world. Characters from Harry Potter make appearances, though it's not so much a proper crossover as it's an Original Flavor GO fic with the Harry Potter cast as extras.
 * Comments: Details the second coming of the Apocalypse so perfectly in-tune with the canon style and characters that it feels like you're meeting and becoming enthralled with the original characters all over again. And yes, the Harry Potter characters are IC too.

Sparks by Afrai (Slash)
 * Recommended by Solandra, Ms. Byrd, Rain Krystal, Baywoof
 * Pairing(s): Pepper/War (yes, really)
 * Summary: Pepper's all grown up, but she's restless about her life until she meets a certain Horseperson who has something eating away at her that she can't name. Somehow, the two give each other what they're looking for.
 * Comments: Makes the Crack Pairing work beautifully by showing how the two redheads' personalities attract and play off on each other, and how humanity might just be affecting War as it did a certain angel and demon.
 * Ms. Byrd is sure Pepper would be horrified to learn that this fic strikes her as strangely and delightfully domestic.
 * Rain Krystal: The prose here is just attractive, I don't know how else to describe it. There's just something about this fic that just sucks you right into it and makes you believe that this truly, awfully cracked-out pairing is actually possible.
 * Baywoof: Wow. The writing is great, and it's amazing how convincing Pepper/War is.

Great Are The Myths by Daughtersofisis
 * Recommended by Solandra
 * Pairing(s): Aziraphale/Crowley near the end
 * Summary: The world is fine, but Aziraphale and Crowley are still tense and anxious. Aziraphale suggests to Crowley that they check with their superiors for peace of mind. Unfortunately, they don't know the full details of portal-opening...
 * Comments: A satisfyingly long work that answers the So What Do We Do Now? question facing Aziraphale and Crowley at the end of GO canon. How the two beings cope with their anxieties in the wake of the Apocalypse That Wasn't are dealt with thoughtfully without ever descending into Wangst. Even their eventual Relationship Upgrade is done in an in-character manner that doesn't need big declarations or confessions of love to be believable.

Twofish by A demon of my word (Slash)
 * Recommended by Solandra
 * Pairing(s): Aziraphale/Crowley
 * Summary: Crowley's new hobby is seeing how long other fish survive against his pet fish, The Great White Bastard. Aziraphale drops by in time to witness this. There's toasting to the number of fish killed, and talk about a woman who's being driven mad by her divine sight and a previous experience in a whorehouse. Then there are kisses and merging.
 * Comments: One of those fics that really can't be described without sounding like Crack Fic or Mind Screw. Initially appears to be nothing more than a silly, nonsensical drunken conversation between Aziraphale and Crowley, then morphs halfway through into something achingly beautiful and tender that makes most other Shipping Fics look downright pedestrian.
 * Seconded like heaven and hell. This is nothing like the "close friendship, just add sex" model many slash fics take in getting the characters to get together, no. This shows the creation of a love that actually convincingly looks like it could outlast empires in a way that does the supernatural beings justice. Beautiful.

The Sacred and the Profane by Afrai (AU, Slash)
 * Recommended by Solandra, Idraena, Athenaswings, feral, Book Digger
 * Pairing(s): Zirah/Caphriel
 * Summary: A retelling of GO canon with the angel/demon roles flipped for Aziraphale and Crowley, but the two retaining enough distinctive personality traits to avoid becoming entirely original characters.
 * Comments: Excellently written in Original Flavor, but with a twisted undercurrent to it; this is what Good Omens would have been like if processed through a nightmarish filter of cynicism. It's the kind of fic you read through once for the great writing, then vow to never read again after being left a broken, sobbing heap at the end. As awesome as the twists and reinterpretations are, it's definitely not a fic for easy reading, but that's exactly what makes it unforgettable.
 * I missed the warning about the broken, sobbing heap and read it, and yes it's amazing but by god I am one right now. Started crying on the fourth-to-last page and haven't stopped since. Don't take this warning lightly.
 * Seconded. Or is it Thirded? Either way this was amazing and heartbreaking. Anyone wanting to read this fic better have a box of tissues with them. They'll need it.

Falling Rain by Ariastar (Slash)
 * Recommended by Solandra
 * Pairing(s): Aziraphale/Crowley
 * Summary: Aziraphale and Crowley wait out the Great Flood on Noah's Ark and actually build a nice rapport, much to Crowley's chagrin.
 * Comments: Gets Aziraphale and Crowley's personalities and interactions so effortlessly right that everything else is just icing on the cake.

Everything That Rises Must Converge by Bookshop (Slash)
 * Recommended by Solandra
 * Pairing(s): Aziraphale/Crowley
 * Summary: Aziraphale can't sit on fences, and Crowley wants the third side.
 * Comments: Proof that a fanfic doesn't have to be of epic length to be funny, romantic, and thoughtful at the same time. Done with excellent footnotes, a precise blend of the silly and the serious, and Aziraphale/Crowley interaction that's just understated enough to work.

Traditions by UseTheForceEm (Slash)
 * Recommended by Solandra
 * Pairing(s): Aziraphale/Crowley
 * Summary: Crowley's been given a birthday from Down Below, and he wants to be distracted from the related memories of his Fall. That's when Aziraphale shows up, intent on chewing him out for what he did when drunk some time before. Things do not go as either anticipated.
 * Comments: This fic is a Lemon with explicit m/m action. That said, it's a lemon done right. Neither Aziraphale nor Crowley are derailed into more "appropriate" roles or given corny romantic lines. The plot doesn't throw them into bed right off the bat, allowing them to set their own pace. Even in the midst of the "action" scenes, the characters' quirks and natures (especially the fact that they're not truly human) aren't forgotten, thus avoiding the typical Slash Fic feel of everything else in the story only being a clothesline for the smex. Oh, and it's definitely not IKEA Erotica.

Through Thick and Thin by Kikimora (Slash)
 * Recommended by feral
 * Pairing(s): Aziraphale/Crowley
 * Summary: Crowley accidently gets Aziraphale into some serious trouble. Hurt Comfort Fic
 * Comments: Good job at examining the emotional toll of living a double life especially after (quite literally) going through hell. Manages to mostly avoid Wangst. Somewhat humorously plays with The Only One Allowed to Defeat You and Crowley is awesome.

Gifts by murderofonerose (Slash)
 * Recommended by feral
 * Pairing(s): Aziraphale/Crowley
 * Summary: The Arrangement is exposed. Nobody bats an eye.
 * Comments: Short, cracky, played for laughs.

Trust, Charity, & the Fine Art of Incompetence by violet gallagher (Slash)
 * Recommended by feral
 * Pairing(s): Aziraphale/Crowley
 * Summary: Crowley and Aziraphale are given new assignments to tempt / redeem each other to the other side. Though it is actually
 * Comments: So What Do We Do Now? Continuation Fic with a Relationship Reveal

But For the Grace of by AmberDiceless
 * Recommended by feral
 * Pairing(s): implied Aziraphale/Crowley
 * Summary: "In the Eternal Conflict between Heaven and Hell, some beings inevitably get caught in the middle. How they deal with this conundrum varies as much as the beings themselves."
 * Comments: Crossover with Hellblazer. Funny, cute, and everyone's in character.

Manchester Lost by JAMoczo
 * Recommended by feral
 * Pairing(s): Aziraphale/Crowley
 * Summary: Aziraphale is captured by Hell. Crowley, War and the Archangel Michael break in to save him and set off a second apocalypse. Also introduces entertaining characterizations of other angels such as Michael, Raphael (Aziraphale's adopted father), Gabriel, and Uriel.
 * Comments: A very funny and engaging story. It also engages in gleeful Lampshade Hanging / playing with tropes.
 * Seconded by chibiaries. One of the best Good Omens fic I have ever read, that captures the original spirit of the book. There are many many side splitting instances of hilarity and jawdropping feats of daring, far too many to name. I especially love the fact that Uriel gets attacked quite a bit by inanimate objects. This is one of the few fics that has its own TV Tropes page!
 * Also has a very awesome sequel, Paradise Thwarted with its TvTropes page still under construction

Barghest: The Three Heads of Cerberus by Secret Weapon
 * Recommended by feral
 * Pairing(s): Adam/Pepper and Aziraphale/Crowley
 * Summary: The Antichrist is going off to college and needs Aziraphale and Crowley to look after Dog. Involves petsitting Gone Horribly Wrong, UST, and their Evil Counterpart bosses putting them both through psychological torture.
 * Comments: Watch your head with the Mood Whiplash, it manages to pull off dark and funny at the same time.

The Casefiles of Dr. Darryl Birkett: Counsellor to the Immortal by Dreya Uberwald
 * Recommended by feral
 * Pairing(s): Hastur/Ligur, Aziraphale/Crowley, Famine/Pollution, Shadwell/Madame Tracy, Adam/Pepper, and Brian/Wensleydale
 * Summary: Couples counseling for immortals starring Original Character Dr. Darryl Birkett, Expy for Dr. Phil. This is why There Are No Therapists. Takes place about a decade post-abotchalypse.
 * Comments: Utter crack, hilarious.
 * Seconded unequivocally by Thinks Too Much. It's very in-character (as long as you assume Crowley was at least exaggerating about the marmalade...), laugh-out-loud funny, and you really start to feel sorry for the poor therapist, who misunderstands just about everything supernatural. (Also it's not Adam/Pepper unless you really squint; all the Them come in together. The Brian/Wensleydale doesn't require squinting, and contains the memorable line "Relationship? I thought you two were just occasionally having casual sex." (No, the story doesn't treat this as the most logical statement ever.)

Arrangements, by Icarus-Chained (Crossover with Supernatural)
 * Recommended by PitViperOfDoom
 * Pairing(s): Aziraphale/Crowley, Dean/Castiel, Sam/Gabriel
 * Summary: Team Free Will meets everyone's favourite angel and demon, and it all spirals from there.
 * Comments: One of the best Supernatural/Good Omens crossovers out there, in my opinion. There is a lot of shipping in this one, but the deep exploration of the relationships between Aziraphale and Crowley, Sam and Gabriel, and Dean and Castiel is what really makes the fic work. The scenes in this fic range from jaw-droppingly awesome to downright heartbreaking, and the interaction between all the characters is vivid and believable. Deserves its own trope page, I think.
 * Seconded, seconded, a million times seconded by Rain Krystal. This fic is one of the best GO fics I've read in a while, and even though I was never a fan of Supernatural before I read this, I am one now. The story is good, but what drives it up to the epic level is that mixed in with all the action and the awesome are these incredibly personal, character driven moments that make your chest ache when you realize you've been holding your breath. The characters make the plot go, and it goes where's it's going at a good pace, taking everyone involved for an amazing ride along the way.
 * This author has also written a number of other Good Omens/Supernatural fics, some of which are tremendously funny, others heart-wrenching (and sometimes both at once), but all of which feature amazing characterisation and excellent writing.

A Diamond Sky Above Titanic by Seablue_eyes
 * Recommended by Pickled Plums
 * Pairing(s): Aziraphale/Crowley, one-sided Asmodeus/Crowley
 * Summary: The year is 1912, and one angel and one demon's lives are about to change forever as they embark on the fateful maiden voyage of the R.M.S. Titanic - and a relationship utterly forbidden by both Heaven and Hell.
 * Comments: Yes the plot comes from the James Cameron movie, but this fic manages to capture all of the magnificence and drama of the movie while maintaining an original plot thread, and portrays Crowley and Aziraphale wonderfully in their roles as star-crossed lovers without descending into melodrama or wangst. Just a warning, you're going to need tissues by the last few chapters, particularly if the movie hit you pretty hard to begin with!