Dragon Age, no contest. Game of the decade as far as I'm concerned
Honorable mentions go to borderlands, batman, and I've heard uncharted 2 was very good but I don't have a ps3. l4d2 will likely be great, but nothing surprising, mw2 can suck a dick, assassin's creed 2 will be much better than the first one but that will only put it on the level of a good solid game, and bioshock 2 won't be out this year