Episodes eleven through fourteen of Ergo Proxy. There's so much existential mindfucking in this show, it'd make Evangelion green with envy. While it's brilliant in its writing, subject matter and its execution (okay, this one's debatable), and artistry, it's a real shame the quality of the animation and consistency of the art go straight to shit starting from this point. Should also mention I'm watching the show dubbed in English, where the script is vastly superior to its Japanese counterpart. The voice acting, overall, is decent, with the major standout being the voice actor who plays the role of the "Memory Recovery" Proxy in episode eleven, Anamnesis. That had to be the best piece of voice acting I've ever encountered in a dub.
Highly recommended to those looking for brainy, philosophical (read: slowly paced) cyberpunk. Oh yeah, and Re-L's a total babe. :D
*Pointless trivia: I first heard of the "GAP" (Gothic-American Princess) in Big Wolf on Campus and thought it was a made-up stereotype, but looking at Re-L, that might not be the case. :O*