Sorry to be unoriginal but Fallout 3. What a fucking slap in the face after 60 hours of growing into your character...
Seriously? It took you 60 hours to beat this game? I don't think I played for 60 hours total between my good karma character and my bad karma character...
But seriously yeah the ending was pretty fucking sorry. "Here's a glorified PowerPoint of you walking into the sunset, the city at sunset, random panoramic views of the country side at sunset..." blech. I also hated how whether you were good or bad effected such minor stuff through the whole story. There should have been two drastically different story lines with drastically different endings, not this namby pamby slideshow at the end with different narration.
Final Fantasy VII. Made absolutely no sense, I can't even describe it.
You prefer the ending to FFVIII? The bullshit paradoxical infinite time loop ending is ridiculous.
Dev A: "Hey guys our story is really deep and imaginative and people are really attached to these characters... how do we end it?"
Dev I: (has been asleep through the entire process, realizes it just now, and wakes up from an alcohol induced fevered dream, screaming and ranting) "OH GOD INFINITE TIME LOOP!"
Dev A: "Nice... Run with it."