Black Lagoon's presentation was very good. It is able to balance out action, humor, and drama quite well. A lot of the character interaction is highly amusing (ie. Rock/Revy, Revy/Eda, etc). The series also pays homage to cultural references, ie. Terminator, "Heireken (a play on Heineken beer)," which add to the slick humor found through out Black Lagoon. The concept is simple, but the presentation is great. So if you're looking for a good action series with style and slickness brought out by in-depth badass characters, Black Lagoon is the series for you. I can only hope for a third season.

Although this is primarily an action anime, there were a lot of parts which made me laugh. However, I've heard one or two people say they didn't find any of it funny. So the humour in this series may not be for everyone. It's also definitely not a series for younger people since there is much violence and various other mature content to be found.
As I mentioned earlier in the review, whilst the story isn't spectacular the relationships between each character is. Rock and Revy are probably the most entertaining to watch but pretty much all the relationships between every character is interesting in some way or another.
The series threw quite a lot of action into it's short 12 episodes, but that's not the end of it.