1. S.T.A.L.K.E.R. - Shadow of Chernobyl
Originally set to be released in 2001, it kept being postponed and postponed. So much in fact that it was starting to be compared to Duke Nukem Forever. And while rumors of it being 'vaporware' still persist, it now has a confirmed release in the first quarter this year.
It's said to be a tactical FPS in the style of Deus Ex, so I'm very excited about this game.
2. Crysis
This will be the sequel to Far Cry and is set to redefine graphical realism in games. No doubt it will require a top of the line PC to enjoy it to it's fullest, but this is the sort of game that makes it rewarding to upgrade your hardware.
3. GTA IV
Set for a release in the 3rd quarter this year. Little is known about the game, but no doubt there will be more information released throughout the year. Considering how great the previous games have been, this game is sure to be another big hit.