Easily:
Metroid Prime 1, Rogue Squadron 2, Resident Evil 4 (Gamecube)
Gears of War 1, Mass Effect 1 (Xbox 360)
Uncharted 2 (PS3)
Half Life 2, Crysis 1 (PC)
I think Metroid Prime & Half Life 2 were the most 'wow' for me in terms of gameplay & graphics.
Still one of my fav games of all time. Can't wait for MP4