Artwork and animation is a big factor for me when deciding which shows to watch. My favorites:
Gankutsuou. Already listed above but worth mentioning again. It's amazing how the animation quality never drops off during the course of the series. Too bad not all Gonzo series can be that way (coughSpeedGraphercough).
Heat Guy J. A bit more traditional, but still very nice. It's like Escaflowne but in an urban metropolis setting, animated with more modern techniques.
Kaleido Star. Who can resist the performances?
Paradise Kiss. Other people have complained about its artwork, but I like it a lot. It's very nicely stylized, coming off as rich and detailed.
x_rex30 wrote:I find that the art in Rahxephon is amazing from start to finish. It has some really nice animation throughout it as well. The entire thing was a visual feast. It was just beautiful to see. I hope to see more series like it.
If you haven't already, you might want to check out Twelve Kingdoms. Its setting is very different from RahXephon's but the character designs and color palette are pretty smiliar. And it's an awesome series all around, to boot.
![Razz :P](./images/smilies/icon_razz.gif)