Ergo Proxy is basically another puzzling, post-apocalyptic view of the future, which had the potential of being a superb show but there was way too much talk in this dreary show.
The first couple of episodes have a "Ghost in the Shell" feel to them, where only the setting is explained and not much is given away, forcing you to figure it out yourself. This show does a terrible job in it's explanations as it force feeds the viewer with so much jargon and it's only the illegal fansub version that will help it all make sense, with their notes.
Beyond this problem there is a brilliant story that focuses on three main characters: Vincent (an immigrant with a hazy past and something special about him), Re-l (a detective in search of the truth) and Pino (an infected auto-rave). It isn't long before these three superb characters are thrown into a journey of self discovery and the stuff they discover is interesting and does a great job in revealing the link between Vincent and the title of this show "Ergo Proxy". In the midst of all this there are some spectacular action sequences however this occurs so rare that the show tends to get boring.
The production quality of the anime is way above average with animation so great you wouldn't want to blink. The artistry is amazing having a mix of 2D animation, 3D modeling and CG that go so well together. The action sequences are what show the full effect of the amazing animation where so much detail is put into every frame and what makes it even better is the slow motion effect. The only issue can be crowds, as the character models tend to degrade in quality when dealing with a lot of people.
The music is basically a compilation of alternative music that goes well with the eerie, moody atmosphere. For people who are fans of bands like Linkin Park will definitely like the opening and ending theme that will get you involuntarily humming the tune.
Overall this was a great show which had so much potential but with the lack of action, the superb animation does feel a bit wasted, plus there's all the winding talk. The 1st half of the show was done well but it did go downhill a bit in the 2nd half, where times when it's hard to tell if something is real or some kind of dream. There were also some incredibly stupid and weird episodes that attempts to be original but fails miserably. The show ends with some very confusing three episodes, which require a lot of thought to make any sense. So this anime is really just for people smart enough to understand its very obscure story and doesn't expect much from the action department.