Comprised of two seasons and 26 episodes, The Big O is a show that wears its influences on its very large sleeve. It is Batman with giant robots and a film noir style of storytelling. The first thirteen episodes are very episodic in nature with only a few ties to each following and previous episode. The final thirteen episodes have a more over-arching story that tries to answer all the questions from season one while posing a few more that might or might not be answered in the final episode.
I really love this show, but it is not for everyone. There is a lot of talking in this show and it is the talking that drives the story. Sure, there is action, but it's the narration and characterization that really make the show worth watching.
Now let me get to the actual story (such as I understand it)...
40 years ago an event took place that caused people in Paradigm City to lose their memories. Since that fateful day people do what they can to get by with technology they don't fully understand or they choose to shun the technology and live off the land (since the land is largely shit they basically live in poverty). At the center of the story is Roger Smith, a negotiator who provides services for people in need when he can. Roger is our Bruce Wayne character, but his alter ego is not a bat suit but a large robot (called "megadeus") named "The Big O." Roger doesn't understand how or why he can pilot The Big O so well, but there is some sort of strange connection between the two that kind of gets explored.
Later on in the series Roger Smith suffers from strange recurring visions that might or might not be memories. Since memories are something that no one seems to have, it is difficult to say what memories actually are in Paradigm City. But Roger sees an apocalypse happening, fire everywhere, and megadeuses destroying everything or possibly fighting to keep everything from being destroyed...
But what does this have to do with Roger? Why does he see this?
All the while a corrupt politician named Alex Rosewater is planning on becoming Paradigm City's new God and he plans on re-creating the event from 40 years ago.
Honestly, there are not many answers by the end of the series. What exactly happened 40 years ago is never totally explained and what happens at the absolute end of the series sort of takes The Truman Show, The Matrix, and a big ole bag of "what the fuck just happened?" and places it all into a blender and serves it to us. I've seen the show multiple times and I can sort of figure it out, but there is no definite "this is what it all means" moment.
A third season really might have helped, but the second season didn't get good enough ratings to warrant one, I guess. Hell, I'd settle for an OVA (original video animation aka an anime feature) to at least tie some of the unresolved issues together.
Final Note: Steve Blum is one of my favorite voice actors and he is perfect for Roger Smith; I could listen to that guy read the dictionary and be reasonably entertained by it. And hearing his Cowboy Bebop co-star Wendee Lee as the strange woman named Angel is a real treat, too.