X-Force/YMMV

Author's Saving Throw: When Rob Liefeld quit the title, Fabian Nicieza famously salvaged the team by writing out Cable and bringing exiled New Mutants Sunspot and Rictor back to the team, as well as New Mutants supporting cast member Lila Cheney, as well as shifting the tone away from the grim and gritty to focus on team interaction amongst the core New Mutants holdovers. Furthermore, Cable came back to the team, less angsty and more stern but lovable father figure-like, Feral was written out, and Shatterstar was given a crush on Rictor that gave him more depth than being a generic warrior dude.
Ho Yay: Rictor and Shatterstar. Recent events have made them a fully canonical couple.
Rescued from the Scrappy Heap: Cable was at one point almost a poster boy for the excesses of 90's comics. He's since been turned into a much more well-rounded character fighting an endless war against an immortal, nearly invincible enemy.

They Changed It, Now It Sucks: A lot of "Liefeld-style"(angst, anger, guns, and innuendo)X-Force fans refused to have anything to do with X-Statix.

Complete Monster: This incarnation of X-Force was put together for the purpose of wiping these off the face of the Earth. The Purifiers, Reverend Craig, Selene, etc. Arguably the only one to whom this doesn't apply is Eli Bard. He's just a guy gone completely insane over his miserable eternal life and desperate for someone to love him. Unfortunately the only way to get the one he loves to love him back is to kill millions of people. Which he doesn't have a problem with anymore thanks to a few centuries of crushing loneliness driving him ALL the way round the bend.
Crosses the Line Twice: Elixir, a much kinder and more peace-loving member of the team, gives Vanisher a fatal brain tumour? Harsh and a little bit depressing. The revelation that he made it the shape of the X-Men logo? Hilarious.
Nightmare Fuel: Rahne's new, more bestial werewolf form is unsettling at best, but after she's kidnapped and brainwashed by The Purifiers, she rips off Angel's wings, then ends up killing and eating her father(though that son of a bitch really deserves it for what he did to Rahne in the first place). So yeah... Or there's ArchAngel going Ax Crazy and killing most of the "Choir" that had wings grown from his and then falling insensate on a pile of corpses. Or...actually, there's some every few issues. Take your pick, though they're all trumped by the sight of Kimura slowly slicing off X-23's arm with an electric saw.

Crowning Moment of Funny: Deadpool singing Miami Sound Machine's "Conga," while being tortured.
Fridge Brilliance: Why did Weapon Infinity go after Fantomex, who killed Apocalypse, when he removed the one thing standing in their way of omni-versal domination? Because he's making a new Apocalypse.
Out-of-Character Moment: Captain Britain. In a massive way. From wanting to wipe someone from existence to completely forgiving his slave-trading older brother, you have to wonder if the writer knows the character is one of the good guys.
Strangled by the Red String: Fantomex and Psylocke.
- Later turns out to be invoked. Fantomex knew Psylocke didn't really have feelings for him, but he had to make her question her devotion to Warren in order to acquire the courage needed to kill him.
Unpopular Popular Character: Deadpool is tolerated at best by the rest of the team and actively despised by Wolverine. Most egregious example: when Fantomex shocks the team by killing kid!Apocalypse in cold blood, Deadpool takes the brunt of the team's wrath for openly questioning the killing. Leads to Dude, Where's My Respect?.