Halo 3, Wolfenstein: Enemy Territory, Half-Life 2 (and its even better Episodes), TimeSplitters: Future Perfect and good ol' GoldenEye. I never say no to a spot of Medal of Honor, either, although I haven't played any of the new generation ones.

If we're including non-FPS, then Gears and Gears 2 are obvious contenders. Hell, Saints Row 2 and GTA IV could also be thrown in there.