My name is vamp, and I've been a part of online fandom since the early 2000's, though back in those days, all I was really doing was lurking, reading, and writing a lot of really bad fic that I never shared. Buffy et al was my main fandom then, but I also loitered on the edge of the Harry Potter and Star Trek fandoms.
I basically left fandom between 2006 and 2008, because I was having babies and they were my focus, but came back in 2009 when I was hit hard with the fandom bug again. I've been here ever since, sometimes right in the thick of things, more recently, skirting the edges because where fandom was wasn't a very nice place to be *cough*Tumblr*cough*
Lately, I have a renewed sense of hope and excitement in regards to fandom, as it returns to old places like Dreamwidth, and enters new places like the fediverse.
As far as my fandom endeavors, I write fic, and I read a lot. A couple years ago I was on a gif-making kick, and posted a ton of mostly Supernatural gifsets. I've archived them off tumblr on their own dedicated site. You can find them at wefoundthebatcave.
My main fandom right now is Supernatural. In the recent past, I spent a lot of time in Teen Wolf fandom (and it takes the award for the fandom I've written the most fic in), and dabbled in Harry Potter. Back further, of course there are fandoms I just want to forget ;)
Buffy the Vampire Slayer is my One True Fandom. Nothing will ever take it's place (though my love for Supernatural comes really frickin close).