Legal Drug
Legal Drug is the only fandom which has managed to suck me in through Manga alone.
A Clamp manga no less. 
And only three volumes of manga at that. The woefully
incomplete, three-volume story of Rikuou and Kazahaya had me for
a bitch the second I pulled it off the shelf of the Barnes & Noble
store. The beautiful and seemingly fragile Kazahaya and the strong,
handsome (sarcastic) Rikuou is a very classic kind of couple
despite their gender. It's always nice to see an old-fashioned
"Seme rescues Uke from the grip of danger" story. Both
protagonists have dark, mysterious pasts that, thanks to
Clamp apparently dropping the series, will probably never be
fleshed out. But this mainstream supernatural-themed manga with
shonen-ai flavor is so beautifully drawn and the characters play
so wonderfully off each other, that I find myself able to forgive the clifhanger nature of
the series. At only three volumes, it represents a very modest invesment, and I
recommend it to anyone who has a spare $30 burning a hole in their pocket.