Half-Life (series)/Awesome Music

Note: Blue Shift and Opposing Force's soundtrack was replaced with Half Life's if you bought a Steam copy. Keep this in mind if you plan on making Justifying Edits or corrections.

Black Mesa (Half Life 1, Opposing Force, Blue Shift, Decay)

 * Electric Guitar Ambience is simply brilliant in its majesty.
 * Most people won't think of it at first, but it helps create an ambience like no other, being so alien, so naturally Space Ocean has to be here!
 * How did we get this far without Nuclear Mission Jam?
 * Awesome enough to be reused as the intro music to Episode 2.
 * Diabolical Adrenaline Guitar. To date it's appeared in HL1, Opposing Force, HL2, and possibly in Blue Shift. Each time, it's during one of the most action-packed areas in the game (the first big soldier fight in Half-Life, the cleanroom scene in OpFor, the canal chase scene in Half-Life 2).
 * In a similar vein is Half-Life's credits theme and its remix in Half-Life 2. Both tracks are still fairly oddball, but actually have a somewhat jovial mood and, uniquely, human vocals. It's the perfect way to celebrate Gordon's accomplishments and cast a hopeful light on the state of humanity, which offsets the weight of each game's suspenseful and ambiguous endings.
 * The final boss theme for Opposing Force, Alien Forces, has a lot of stopping power. The alien things have mustered a huge portal underneath Black Mesa, there's a titanic living WMD about to crawl through to our world and it hinges on you to stop it. Now put on your war face and march, Corporal. You have an alien god to punish.
 * Hard Technology Rock. A minute and a half of pure headbanging awesomeness. Not to mention it's played right when you get to use a freaking tank cannon to absolutely destroy a group of aliens.
 * The VALVe theme song, also known as "Hazardous Materials", is especially awesome when the extended version is played when Gordon gets his HEV Suit back in Half-Life 2.
 * Its first appearance was in a psuedo-boss in Surface Tension, in which you must scale a thin cliffside while facing off against a turret, HECU, and an Apache.
 * The army's bombing the crap out of your place, and the way back is locked out. Better start runnin'.

City 17 (Half Life 2, Episode One, Episode Two)

 * Two Words: Vortal Combat from Half Life 2: Episode 2.
 * Not to mention it's coupled with a Crowning Moment of Awesome.
 * This troper always like the short but sweet "Triage at Dawn." Apparently there's a few longer remixes out there, too.
 * Also, it was featured on Lambda Generation. See the top 5 remixes here
 * There are, and they trump the original version many times over.
 * Moment this song was played was made especially unforgettable by the fact that it is the first time you see allies after long, dark and gory adventure through ghost town and demon mine.
 * The long version always makes me want to cry. I think about Winston and and all the people who have died because of the Combine--or, even worse, have been mutilated and... changed into Combine soldiers and stalkers--and I can't help but feel a little sad inside.
 * The intro to "Nova Prospekt" is quite fitting.
 * "LG Orbifold," the music for the chapter Follow Freeman, when our crowbar-happy hero is back and leading the revolution.
 * "Apprehension and Evasion," for when you're being chased by bullets through a train yard, armed with only a crowbar. Always just as tight, no matter how many times that one scene is played.
 * Even better, it plays again when you and a swarm of antlions raid Nova Prospekt.
 * Last Legs for the final boss battle song! Autobots Rock Out!
 * Ladies and gentlemen, witness the awesomeness that is C&C music remixed with Last Legs: Half Life: Last Legs (Command and Conquer remix).
 * Nothing says "the vehicle sections in Episode Two are so much more awesome than Highway 17 was" than Sector Sweep.
 * The awesomeness of the obligatory strider battle of Episode One is multiplied by Penultimatum.
 * Not to mention the little signature Half-Life motive which appears when you regain your crowbar from Barney. Goosebumps right there.
 * Episode 1 had its own share of awesome themes: Disrupted Original, What Kind of Hospital is This and Episode 2's Abandoned in Place.
 * Gawd, we're gonna list every single song on Half-Life's awesome soundtracks, but... The public must know! How about some CP Violation? It's not head-rockingly awesome, but it aptly reflects how the CP units (and by extension, the trans-humans in the games) are a fusion of familiar and alien concepts.
 * No love fore Guard Down? It happens as soon as you kill the Antlion Guard after escaping the Hospital. And then, the music leaves you feeling like you literally let your guard down, and that this moment of calm will only be met with more firefights. Also it's awesome.
 * Ravenholm reprise. Short but sweet.
 * ...And even after you're about to leave the condemned Ravenholm, Requiem for Ravenholm will ensure it never leaves you. In my opinion, the single most powerful piece of music across both games.

Mods

 * Neotokyo, a mod for Half-Life, has some great original songs composed Ed Harrison.
 * Tin Soldiers is a great one
 * Scrap I/O
 * Annul
 * The main theme for Black Mesa. It's very different from the usual electronic music you listen in the games, but it fits perfectly when you think how bleak Gordon's situation during the resonance cascade incident is - he doesn't know if his friends are alive, he has to fight constantly and even against those who were supposed to be the survivors' saviors, and things just get worse no matter what he does. It just pictures him having time to take a break, sit down, and think of everything that has happened, and still is.