He is asking for PC only games.Silent Hill Home Coming is gory
also Ninja Gaiden Series
God of War
Try Saw:The Game.
Never played it, but saw a trailer once.
uh nobody mentioned postal? you get to use kittehs as silenzers
My vote for
Manhunt, Postal 1|2, Blood Rayne, Prey and Ninja Gaiden (the recent one is for PC)