Hellsing Ultimate, just to get ready for vols. 5-8 I am rewatching 1-4.
Still all sorts of awesome.
Though it's not for kids, so keep them away.
Also even though it's been said before, I will say it again.
If you watch it make sure to watch in English, cause the dub is beyond excellent.
A mess of blood, violence, and bad words are thrown around a lot.