A note: This review covers both Black Lagoon and Black Lagoon: The Second Barrage, and the score is a composite of the two series. If I were to rate the two seasons individually, I would most likely give season 1 around a 7.5 and season 2 around a 6.5.
Black Lagoon looks like a mindless action series. It smells like a mindless action series. However, it is not, by any stretch of the imagination, a mindless action series.
To be sure, Black Lagoon almost certainly has mindless action in it. Minor characters spew streams of automatic fire at the protagonists without so much as scratching them. Buildings and vehicles explode at the slightest provocation. Villains emerge from flaming wreckage completely unscathed. Without doubt, these scenes are completely brain-dead, but this is not really what Black Lagoon is all about.
In fact, more than three quarters of the show is reserved for dialogue. One might think that this would slow down an action series, but instead it is easily the best part of the show. Put simply, the show's script sparkles with wit and intelligence. Through an interesting blend of obscure pop culture references, serious philosophical debate and hilarious one-liners, Black Lagoon has some of the best writing of the year.
Unfortunately, Black Lagoon is hampered by a disappointing final arc. The ending drowns itself in a seeming avalanche of petty plot details that I didnt really care about, and the things that made the first season so great (the black humor, interesting philosophical discussions, and risqué attitude) are almost completely gone. In particular, a large part of the normally excellent dialogue is carried out in English. While all of the English is grammatically correct, it's hideously voice-acted, almost to the point of being unwatchable.
In fact, as a whole, the storyline is somewhat uneven. Some of the episodic arcs work well (in particular, the Twins arc at the beginning of the second season is wonderfully creepy), but others either are too ridiculous to really take seriously or get bogged down in unimportant details. Fortunately, as mentioned earlier, the story usually takes a backseat to the dialogue, which is fantastic.
The technical aspects of the show are serviceable, but certainly not outstanding. Animation-wise, the show looks fine most of the time but seems unsure of itself when it comes to the action scenes. Some scenes literally consist of two characters running in a straight line while shooting at each other, and are somewhat dull to sit through. Still, the character designs and backgrounds are top-notch.
There are a couple of problems with the sound. For one, the show leads into the ED at the end of every episode. This slow and depressing instrumental piece is often at odds with the frenetic action that has happened right before it, and serves to dampen the mood of the show. Also, the aforementioned switch to spoken English represents a key misstep in my mind. Fortunately, the OP and non-English voice acting are both great, so Black Lagoon's sound isn't a complete failure.
The wonderful dialogue serves to create characters that feel much more real than the cookie cutter clichés that have come to dominate most of today's action series. Despite the inherent ridiculousness of the setting, all of the characters are believable and likeable. In particular, the two primary protagonists, Rock and Revy, are fantastically well-developed and serve as primary illustrations of the show's theme of moral relativism.
As a denizen of the "normal world," Rock represents the core moral values of modern Japan. Conflict is wrong, life is sacred, good and evil exist, etc. Then, over the course of the series, his traditional beliefs are challenged again and again and again. These beliefs are most apparent in his conversations with Revy. In the beginning, whether he can help it or not, he judges her. He sees her as a thoughtless, cold-blooded beast, an amoral killer that should be both despised and pitied. However, over the course of several heated arguments, Revy slowly shows him that he cannot judge her, because he has no experience whatsoever in her world. He is an alien, a visitor. He does not live in the "night" like the rest of the people of Black Lagoon's accursed city of Roanapur (where even the church is corrupted); he can only peek in through the "twilight." Combined with the characters, this moral "twilight" is ultimately what makes the show what it is.
In many ways, the show strongly resembles Cowboy Bebop. Both series can superficially be written off for their action or episodic plots, but both have significant and interesting things to say about the outcasts of society. While Black Lagoon fails to match Cowboy Bebop in sheer execution, the anime is certainly a step in the right direction for the otherwise increasingly derivative action genre.
Rokuro Okajima is a small-time salaryman who is carrying documents for his company, when the ship he's traveling on is attacked by pirates. Kidnapped, he discovers to his dismay that his employers' main concern is to ensure the documents don't get into the wrong hands, even if it means sending the carrier to the bottom of the sea. Now, with his former life ruined and his kidnappers seeming comparatively friendly, "Rock" decides to join their merry band of mercenaries, and sets out with a new career to the shadier corners of the South China Sea.