This gives me an idea for a cool D3 (or HL2, FC, U2k4, whatever) mod...FATALITY MOVES!
We love it when the game acknowledges a great accomplishment (headshot, rampage, etc.) so why not a system where, after you have killed someone and their corpse is lying dead, you do something on the keyboard, and then, WHAM! you stick your fist into their chest and rip out their heart!!!! Or spine, intestines...whatever. Maybe go into 3rd person too.
It could turn into a gameplay mechanic, you're vulnerable to other attackers, but you get bonus health or something for doing it (and a