Check out Dead Alive. Its not a straight horror movie though, its a comedy/zombie movie, but it has the most blood of any movie ever. Peter Jackson directed it. The Unrated versions called Brain Dead.
I havent seen a good horror movie in forever, I think the last time anything ever freaked me out was when they rereleased the Exorcist and that fucking demon/dracula head that was in the background bugged the shit out of me