I've seen the first 3 eps of Black Lagoon which looks pretty interesting if dark.
This montage on you tube uses the opening credits song to give a good idea of the feel of the series.
A grim, darkly humorous action, crime, and..er fanservice tale, the show is essentially an updated, serialized and animated Chinese gangster film. It revolves around the 4 person crew of a South China Seas pirate vessel, the BLACK LAGOON (a restored Elco PT Boat). The first 3 episodes concern how "Rock", our average Japanese sallaryman and posterboy for stockholm syndrome manages to end up as the bookkeeper for a band of modern day pirates. This sort of show generally doesn't appeal to me but the characterizations are quite good, and the mechdesigner loves his military kit :).
The show is pretty good about setting up a realistic (looking) view of the corrupt armpits of humanity that make up the pirate infested and lawless world between the Phillipines Thailand and Indonesia. It is being released on DVD by Geneon in April. I'm looking forward to the rest of it.