Anons who are fans of the Big O, I implore you to watch Giant Robo. Earlier series which a good chunk of the Big O staff worked on, it's an amazing series based on the OG mecha manga while also blending a bunch of influences together, from romance of the three kingdoms to opera. It's worth it for the animation alone, but the whole package is something else.

It's available in full on youtube so there's no excuse not to watch it: https://www.youtube.com/watch?v=cdqdbXJauIg&list=PLFGrvOxPs00Snml-G9jdNdD9vdjqRMkev