I've been writing fanfic since before I knew what fanfic was, although most of my earliest work will never see the light of day. :-) My first on-line fandom was Quantum Leap way back in 1995, and it's one I occasionally come back to even now.
I love time travel, and as a result am currently obsessed with Doctor Who above and beyond all my other current fandoms, but I'm way too easily distracted to ever settle entirely into one groove so I'll bounce over to other fandoms still sometimes. Favorite genres are crossovers and AUs--the bigger the "what if?", the better I like it. :-)