Nice reply, Jorath!
Seriously, Elfen Lied(pronounced Leed like in German) was quite a bloody anime series that also has full frontal nudity in it. Due to massive amounts of the aforementioned features(flying limbs and the like), I think it's never going to be dubbed to English.
The old classic 1988 anime movie Akira and the Neon Genesis Evangelion epilogue movie End of Evangelion are also pretty violent. They weren't nearly as violent as Elfen Lied but IMO they were more effective.