[Boudica]

I reccomend Deadman Wonderland to anyone who hasn't seen it

Having just recently binge watched it, I can say that's a great recommendation!
I've seen things like Corpse Party: Tortured Souls, which is more gorey than anything. When you say dark, do you mean stuff that's a little more thought provoking? I tend to like that sort of thing, but find it hard to identify a genre. I often find those shows listed under other genre's like Fantasy etc.