I finished watching Ergo Proxy a little while ago, and I must say, I absolutely LOVE the show. The concept of this anime is quite philosophical and it revolves around the ideas of Renee Descartes, particularly the phrase, "Cogito Ergo Sum" (which means "I think, therefore, I am"). It's post-apocalyptic, artfully done and the characters are engaging individuals with layers to their personalities. The protagonist is a girl named Re-L Mayer and as you can see, Re-L is a play-on word for real. She is definitely the most 'real' character among all the rest. I love how badass she is!
"There is no meaning in conflict, but there is meaning in destruction"