Final Fantasy VII
Butterfly Effect, by Bard Linn and Kiraya.
Summary: A FFVII AU that follows the premise of a young Cloud Strife finding Vincent in the basement of the Shinra Mansion by accident. This changes everything, from Cloud's reasons for joining SOLDIER, to the events of the Nibelheim Mission.
My Review: I really like this fic because, although it uses some of the themes that have become way too over-done in this fandom, it does it in ways that work and don't seem trite or unrealistic. I especially like that, even though there are hints of potential romantic pairings, both het and slash, they are not the entire point of the story- or even a small part of it. The characters are all realistically portrayed, with no bashing or over-dramatizing of certain character aspects, and the relationships (friendships, acquaintances, co-workers, ect.) actually make sense. The story itself is actually pretty unique in ways that I won't go into here, simply because it does not religiously follow the game (even though it's technically pre-game for half the story) but still takes into account the bits of cannon that probably would not be effected by the changes made. If nothing else, read it for competent, non-emo Cloud, fun, yet still well-rounded Zach, non-insane General Sephiroth, fairly portrayed Aeris, likable Tifa, and the ever-cool Turks. Mostly though, read it for non-angsty, Vincent who actually uses the talents he would have had as a Turk... and also his demons, who actually seem to be important to the plot.