My first fandom was Starsky & Hutch. I discovered that fandom existed and that I wasn't 'strange' for the thoughts I'd had, stories I'd made up some thirteen years ago.
I wouldn't say I'm still active in it; I don't consider writing a story every year or so constitutes being 'active'. But then I've been thinking about the whole term 'active' over the last few weeks and what it means to me - which I shall blog about at some point (you have been warned).
I wrote for zines in this fandom; I also participated in discussions on Yahoo Lists. I've never been 'active' in this fandom on LJ.