I agree that Man Hunt 2 was good. Loved the level in the red light district and the brothel where the goons are trying to kill you with a basball bat and you get to kill a guy by slamming his face into a toilet :-) That said I did find the graphic s a bit disappointing. I don't know if it's my immagination or not but I think Manhunt 1 actually had better graphics?! But's it's been awhile since I played it so I could be wrong.
Blood 2 the chosen and its add on pack are gory games that are seriously under rated. A bit old now but still fun if you can get them to run or have an old computer. There was one level where some guy's chopped up in a washing machine and a ghetto bitch says 'he just fell in, it was an accident.'
Not sure about the console versions but the PC version of Manhunt 2 is noticably better looking then Manhunt.
Pretty much every FPS title from the 90s is full of gore. Duke3D, Wolf3D, Doom, Doom 2, Quake, Shadow Warrior, Redneck Rampage, Rise of the Triads and many others.