Another great year for me,
Bioshock, S.T.A.L.K.E.R.: Shadow of Chernobyl, The Witcher, Penumbra: Overture, Crysis, Super Mario Galaxy, Patapon
One that surprised me the most was Assassin's Creed - yeah, it was not perfect, but it felt so unique at the time. I still prefer those controls over modern ones and approach to stealth over action gameplay.
But this is one of those few years were my favourite and what I think the best game match - Portal was not only great puzzle game, but introduced one of the best villains ever - GLaDOS.