BioShock , Crysis , Halo3 , Dirt , Half Life 2 Episode 2 , Metal Gear Solid 4 , Unreal Tounament 3 , Call Of Duty 4 , Medal Of Honor Air Bone
I second Call of Duty 4. It looks amazing and Infinity Ward hasn't let fans down yet. They keep improving the gameplay and the graphics and now that it's set in modern day it should breathe new life into the franchise. Halo 3 is going to be massive but I prefer COD over the Halo franchise anyday.
Crysis all the way. The physics and IA of the game promise a lot! (quadrcore recommended, 1 for IA, one for physics and the other for general processing)