Gory, eh?
Like some people have mentioned, Baccano! is quite violent and gory. One character covers himself in blood and acts nutty for the rest of the series, and one hitman character acts like a less-than-subtle version of Mr. Blond from Reservoir Dogs. Yeah, it's not a very subtle series but I enjoyed it very much. The way they tell the story is quite unique (from what I know): it's done non-linear and "doesn't have a main character". The characters were all likable in their own way though the last two episodes felt tacked on. But where else are you going to find a show about immortal crime syndicates?
But if you don't feel like sitting through an entire series, perhaps you may enjoy the one-shot anime Dead Leaves. Very bloody, violent, and out of its goddamn mind. The art complements this well: no traditional styles or moe here, instead it goes for a sort of graffiti, jagged style. Off the bat, the main characters wake up naked with amnesia and immediately go on a crime spree or clothes, food, and just for shits. My description here doesn't do the anime any justice. Think Superjail! if it was made in Japan and a lot more electronic.