The anime is on the darker side given that the characters we are following are essentially pirates. You have them doing human trafficking, weapon transportation, killing, mafia, grave robbing, etc. The second job they do they are facing off against Neo Nazis of all things! The main male lead is a moral man Rock who serves as a narrator and our entryway into the world of crime on the high seas. Revy is his opposite who has always been lead the crook life and is a wild rough woman. She's not the typical woman you see in anime and is engaging. She definitely serves as the fanservice spotlight in the show but it isn't too distracting as it's more so the "Badass" kind of fan service. Very much so a "2000's anime".
Black Lagoon is amazing as it is one of the few anime with a diverse cast of characters. As other have noted the most development occurs with Revy and Rock. Dutch and Benny are solid characters in their own right unlike what some others have said even if they are more supporting characters even if they are a part of the company. Benny is naturally a more of a side character as a he is the tech wiz and researcher. Dutch is the leader of the company and does his job well.
Personally: The main highlight is the other characters introduced are engaging that go against the company we are following. The backstories provided are fun.
The art overall well done in the anime. The music track I consider to be phenomenal. Realism for action in this anime is 50/50 but the action scenes are fun and rewatchable.
I personally put black lagoon episodes as background sometimes while I'm doing chores other tasks.
Dub vs Sub: I would recommend watching the english dub for this anime actually as the voices are quite fitting given the diversity of the characters from different countries.
