I'd like to try Gears of War. It comes from Epic Megagames (I still use Megagames because I still play that old game of theirs, ZZT.), creators of the Unreal Tournament series and Unreal Championship 2, and since those games are by far my favorites, I'd love to play it.
Why does that matter though? Unless your gut churns at the sight of red flying pixels, it shouldn't matter. (I believe it adds realism to a game--bloodless shooters don't look right to me because the enemies must not have circulatory systems or something...)
I personally don't mind. If I took a chainsaw to someone's throat, I'd hope their head would come off. (Well, in a sense, you know.) If you don't like it, alright, though I just don't mind really.