I don't know, Turok 2's Ceribrovore is pretty entertaining.
I think most of the games with violence in it is not as fun, because eveyone is trying to be gritty and realistic. I mean come on this is exactly the same thing with colours. Brown, grey, black, sometimes white, and with very bleak worn out faded colours of other kinds ooooh, neutral tastic. Realism taking precedence over fun.
If it's a detail thing then it makes sense, like in Halo you shoot an alien it bleeds a different colour, it doesn't bleed red it bleeds blue so it convinces me more that it's different.
(Mirror's Edge sucked, only the demo was good.)
A tool is a tool regardless. I mean if you suck, you suck, and not even the most perfect tool could save you. And if your damn good then even with the worst tool ever conceived you could chug out some high quality shit.