In my travels recently I picked up a copy of Aliens vs Predator. It has sold less copies than was expected, but it's a great game. Beautiful area design, amazing gameplay, whether hunting marines as the cloaked Predator, escaping your captors as the stealthy but swift Xenomorph or even getting your boxers filled with bricks as the marines as the varius alien species sneak up on you and kill you. Brutally. Extremely graphic kill sequences cover tha game with gore and various other nasty bodily fluids all over your screen, whether ripping the head and spinal cord out of your prey or just chomping through their skull.
I can't be arsed to write another bit on Mirror's Edge, the revolutionary parkour based FPS.
Any other ones you can think of NG?