Let's see...die hard slasher here, with a case of hetsquick. I'm very multi-fannish, and outside of anime I probably have at least a passing knowledge in practically every major slash fandom ever.
Still, the Fandoms I Have Really Loved: Harry Potter, due South, SGA. (In chronological order.)
Through some strange quirk of fate Percy/Oliver from HP are pretty much the only pairing I've ever written. I'm not even that into HP anymore, but, strangely enough, no matter how far I wander in fandom, Percy/Oliver still has a hold on me. Also, I read a lot more than I write (and I write pretty slowly). So, uh, if you're wondering about that Blind Date epilogue I promised, I don't think it's going to happen. Sorry.
However, I am working on a P/O fic set during the 5th and 6th books, though it's obviously pretty damn long and if I ever finish it, it's going to be awhile.