The Big O is a decidedly Western-ish series which has a lot to offer fans of many genres. It has a distinctively noir setting with a crime drama sort of structure infused with plenty of psychological aspects... and of course the obligatory giant robot fight in every episode. What's not to love?
Writing: For the most part, The Big O's story is nothing to really write home about. Episodes, for the most part, are pretty self-contained, with maybe one or two small plot details revealed or expanded upon per episode and not much of an overarching storyline until everything wraps together (sort of) in the end of it all. It's a writing style characteristic of Western young adult animation, and since that was the intention of the creators, one must applaud them. Even better is the characterization present in this series--granted, while the incidental characters are nobody shmucks, all of the recurring characters are very unique, and I don't think there's one of them without at least some likable aspect to them, from the suave negotiator to the lovably dry android, the conflicted cop or the most dedicated goddamn butler in Paradigm... even the villains are full of charm. The characters, for the most part, feel very "real." What really, really hurts the writing of this show is the ending. It's a deus ex machina if ever there was one--a "we wrote ourselves into a corner and had to pull this out of our asses" for the ages. Is it the single worst ending in the history of anime? ...well, I don't know if I would personally go that far, but there are many who would argue that point. The bottom line is, while the series is wonderfully engaging on the ride there, the tail end crashes and burns in an open-ended mess guaranteed to leave the viewer unsatisfied and without closure.
Art: The art is perhaps another weak point of the series. Along with the writing, the art was meant to feel Western by design... and this has been accomplished. That said, it means the production values have suffered a bit and the characters are significantly less detailed and more cartoony due to this style choice. Which, granted, is what it is--a style choice. Nothing to hold against the series, if not for the leap in quality between main characters and bit characters in the show. The stand-ins and background characters look very... well, cut-out. Fortunately, the artists took their time on the main characters, and the robot/machine designs, along with the general setting of Paradigm City, are a sight to behold.
Sound: There are not very many tracks on the score for this series, so be prepared to hear the same music used over and over again. Fortunately, it's all pretty classy and engaging, and I have no problem hearing it repeated. I'm quite fond of the soundtrack--but if you're not, it'll probably get grating. The English dub boasts an all-star cast in the VA community, with such names as Steven Blum, Wendee Lee, Michael McConnohie, and Crispin Freeman, among others, and is directed beautifully, bringing the characters to life vividly and enthusiastically. I haven't spent as much time with the Japanese dub, myself, but seems to hold up just as well with strong dialogue and characterization.
The show really is a very fun ride up until the end. Enjoy it while it lasts, and hopefully the final crash won't kill you. I can recommend this to any fans of Western animation with an interest in or tolerance for the super robot genre... and especially anyone who wants to see Batman busting heads in one.