The twists and turns of Vincent Law's personality and how he matures over the course of the series, the way Lil Mayar is used as a medium to progress aspects of Romdeau and how Vincent Law is connected to it, and the remaining characters of this series (Dedalus, Raul, Iggy, Pino, Kristeva, Monad, Ergo, and the minor characters in between) are handled with pin-point accuracy in my opinion. Nobody stays more than their needed to be, and nobody is under-represented.
My personal favourite in the series was episode 11, where the arguments used in helping Vincent Law understand himself, and I think that the whole key of this series lies in that episode.
Another aspect which I loved of this anime was its artstyle - although dark and gritty, it does give a wonderful contrast to the situation and the settings in which the anime takes place: the way the transitions happens between Romdeau (or for that matter, any other city outside of Romdeau) and the outside world which is in between cities, makes it really sublime. They not only add to the progression of the series, they also add to the environment and the feel of the anime. For me, this is a really well founded anime.
Although this is nitpicking, I think that another aspect which gives this anime a good kick is the subtle influx of philosophical constructs and arguments, as well as the use of literary references. You'll get what I mean once you watch it - oh, and on a conclusion, I think that the best character would be Pino. And I praise her voice acting in the Japanese version.
In conclusion, its a good anime. Amongst the best I've seen thus far.
