I am really loving writing From the Looking Glass (see signature for link). Mainly because its an adventure story before its an erotic story and also because I made the world, the characters and I can feel for them.
FtLG is only in the beginning stages, the protagonists not even fully introduced yet, but I know where its going just not entirely sure how its going to get there. I also like that my characters seem real to me, and if I write them wrong it feels like they're yelling at me for being an idiot.
I have written a lot of Naruto one shots, but I never really liked all of those. The Gai Anko one was fun as hell to write, but the rest were only done because I enjoyed writing with someone, which I am doing more ridiculously in the orgy on the forum games now anyway, so the want to write fanfiction is kind of gone.