Yeah, after you learn all the ways to kill someone, it basicly becomes a "see how many limbs you can shoot off before they hit the ground" game.
Interesting death animations:
Shooting someone in the neck with the sniper rifle
Shooting someone in the midsection of the torso with the shotgun at close range
Shooting any limb with the 44magnum
Shooting someone in the head with the 44 magnum or the shotgun at close range
Shoot someone in the groin