I'm going to give a shot at reviewing my first anime on this site, and see how it goes.
Darker Than Black
Story - 9.0
Overwhelming Tokyo is a mysterious hundred story tall wall, closing off an area known as Hells gate, while superhuman people known as contractors do battle in the streets. This is not the Tokyo you know!
Darker than Black weaves an intricate and methodical story which builds upon itself masterfully. While no one would confuse this anime with a fast moving Shounen, it certainly has a fast enough and well structured pace to its narrative that is sure to keep all but the most ADD anime viewers interested. The anime starts with two 2 episode "world introduction" arcs, followed by a chain of 2 episode character introduction arcs, interrupted at points with several "narrative" arcs, and 2 "comedy/change of pace" arcs, which oddly still advance the story, so they fall short of the classification of filler.
The thread tying all these arcs together and simultaneously driving the narrative forward is the protagonist/antihero Hei (the Black Reaper) aka BK-201 aka Li Shun Sheng and his search for his long lost sister Bai. Strangely though he's close to the center of all of the arcs, he remains the biggest enigma in the anime for the majority of its length. One of the most fascinating games the writers play is their hints at his past which is never fully explained while we are slowly exposed to his past we start to see as an audience just how it ties in with what is happening now, and how all of the story has been woven together.
Animation - 7.5
The animations style is fluid and the colors muted, however nothing about this anime will leap off the screen at you. The trick is, I saw this quality of animation in 2003, and while it remained good in 2007, its grown rather dated since. The combat flows smoothly and the characters remain largely well proportioned, some of the combat physics bugged me to no end. In short, this was good animation, and remains good animation, but it's already starting to show a little age. It’s good, not great. When compared against one of it's contemporaries like Black Lagoon, it really doesn't impress.
Sound - 7.5
The music was alright. Nothing notable. I know some people rather loved the OP and or the EDs for the series, I never really found them much to write home about. What really carried the anime was the soft piano ambient music which seemed to set the proper tone throughout. Throw in a solid voice cast (Kirihara Misaki's VA, Mizuki Nana deserves special recognition) and you have a solid, if not inspired auditory experience.
Characters - 9.0
The characters were a mixed bag, and I really struggled to rate this. On one hand you have the mix of the cliché. You have a deadpan grey haired loli, you have a snarky sidekick (granted it's a cat, so that's a little weird), you have a heavy drinking foul mouth authority figure. What sets these characters apart is the depth granted them. Every major character in this anime got his (or her) own arc, to develop their background, examine their motivations, and advance the plot. Even sometimes antagonist Section Chief Kirihara is well developed to the point she's nearly a lead character in her own right. The lone blemish in this excellent cast is the horrifically bad character "Amber." For a character around which most of the last 1/3 of the anime is revolving, she remained not only a stunningly shallow character, but an annoying "Mary Sue" as well. Granted she had some "explanations" for her inhuman competence and almost god like prescience, but in the end she simply fell flat as either sympathetic love interest, or devious antagonist. In an anime which revolved around a gritty and dark magical realism, she simply never quite fit.
Overall - 9.0
This anime really was greater then the sum of its parts. As a rare well executed Film Noir style anime it stands out. It contains a number of overlapping themes, such as the definition of humanity, friendships, and a person's place in the world. Its short 2 episode arcs make for easy watching. Its deliberate and complex plot lays a number of clues about a number of mysteries, some which are answered (as number of which are left unanswered) at the end. Finally, the anime ends at a point where you the viewer can walk away satisfied. When you consider the engaging characters, the gritty and dark plot, the solid animation style and the well written storyline you're left with a memorable and enjoyable Seinin anime.