Hiyaz! I love Yaoi and write original shounen-ai novels, of course none published as of yet -_-. My favorite Yaoi pairings along with the animes the people are from I'll list below.

Yu-gi-oh:
Malik + Bakura
Yami + Seto Kaiba

Neon Genesis Evangelion:
Kaworu + Shinji

Yu Yu Hakusho:
Hiei + Kurama

Gundam Wing:
Hero + Duo
Trowa + Quatre

That's about it for yaoi couples, but I'm sure I'll stumble upon some more interesting ones later ^_^ BTW: All my work is copyrighted, though characters from animes are not, original characters are.