Make an alternate ending to a game you like.

[Aesir23]

FFX/X-2:

Spoiler

Tidus stays dead/whatever. Bringing him back kind of ruined any emotional impact of the ending.

Actually in X-2 there are multiple endings. If you get the "bad" ending then Tidus stays dead. Though that's still a 2/3 chance of Tidus returning.

 

[pspman45]

Rainbow Six Vegas 1 + 2: make Gabe not such a *****
seriously, the only reason he gives for committing treason, murder, and terrorism is because Bishop always covered for him and never let him take responsibility for his actions
I'm sorry, but that's fucking STUPID!

Skyrim: the end of the Alduin battle should end with a shouting battle atop the throat of the world during a blizzard/lightning storm. Alduin shouts words of his own creation, one that would destroy your mortal essence, and you shout Dragonrend, ending with a special death animation based on what weapon you have equipped. you then absorb his soul and gain a shout that insta-kills you opponent and turns them into a skeleton.
then they throw the BIGGEST PARTY IN THE HISTORY OF NIRN IN YOUR HONOR, BECAUSE HONESTLY I REALLY DON'T THINK AN OCCASIONAL DIALOGUE PIECE FROM A GUARD IS WORTHY OF MY DEEDS

 

[Woodsey]

Spec Ops: The Line

Spoiler

A higher power was behind the events in dubai to test who was "strong enough to deny what's in front of him"

Spoiler

Walker had a premonition of what was going to happen in dubai and decides not to take that mission

Spoiler

Walker sees jesus but a minor detail is show to imply its jesus. Walker salutes and says: "Sir! Welcome to dubai."

Not sure if serious, but: the first two miss the point of the game. The third is just bizarre.

OT: Mafia II. I get what they were trying to do, but since the game peters out in the final third it rather falls flat on its face. Not sure what I'd do instead, just... something.