I discovered fanfiction during my Babylon 5 obsession, but I never really participated in that fandom, because by the time I got into the show, fandom wasn't really active anymore. My introduction to online fandom was Angel, although the show was already off air at the time. Supernatural is my first online fandom for a show that's still on air. :)

And we can agree on GoF being our favorite (nice, you don't see many people saying that! :D)
Really? What is generally the favourite book in HP fandom?