What are some gory free roaming games for PS3?

I get a little stressed out sometimes and like to take my frustration out by killing random people (I'm not a sociopath I can barely even kill a bug without feeling bad in real life) in really gory ways on video games. I can't really find any good free roaming games with what I'm looking for though. What are some games that have free roaming and are really gory where you can go on murder sprees for PS3?