And at number five in my personal top ten for 2008, it's... a match-3 puzzle game?!
5. Audiosurf (PC)
The release of Dylan Fitterer's "music-adapting puzzle racer" in February ushered in the year of the indie game designer. While big-budget, triple-A "blockbusters" came and went, Audiosurf remained on high rotation on my gaming playlist. It worked because it not only adapted itself to whatever music you felt like listening to, but its varied gameplay modes meant it could adapt itself to whatever game you felt like playing. Sometimes I wanted the challenge of a fairly complex match-3 puzzle game; sometimes I just wanted to chill out in Mono and discover how it interpreted some of my favourite music. As a result, I expect this is probably the only game on this list I'll still be playing in five years time.