I strongly prefer light on dark, but hated pretty much every emacs theme I found. A couple days ago, I ported a friend's "IR Black" vim theme to emacs. I'm still not entirely happy with it, but:

http://github.com/burke/color-theme-ir-black/blob/master/scr...

EDIT: Upon further investigation, I believe this color theme originated from http://blog.infinitered.com/entries/show/6 .