There is some comedy being a shounen and all, but when it chooses to get serious....
Either the manga or the anime is good, but I think the full blown effects of this sort of thing are better in the anime.
Spoiler (mouse over to view)
Yu Yu Hakusho But it only "half" counts
What about Trinity Blood? Not the manga though...
I'll edit this post if I can think of anymore.
I like my men androgynous.
I like my women androgynous.