America's Army 2.5.
Take your ultimate humiliation move in your favorite FPS: knifing in CoD/BF, mine traps, headshots, all of these have nothing on the ultimate fatality:
Try beating running up to a guy with an RPG-7, turning so that they are behind you, and taking them out with the back-blast as you send the RPG away. Sadly it wasn't me who did that, but it was an awesome moment to spectate.