In no order:
Battlefield 3 - for the online play, no FPS has come close to this yet for me.
Legend of Zelda: Ocarina of Time - The satisfaction of beating the water temple is worth it.
Bioshock - "Would you kindly?" enough said.
GTA 5 - like San Andreas only much improved.
Best game I've ever played can only go to The Last of Us. Completely absorbing story, wonderful environment, great gameplay. As flawless as a game can get IMO.