Haha, I'd love to say the Potterverse was my first... but I am getting old now and I was already graduated from university before the first movie came out and I got into it (thanks to a small child watching it twice in a row). My first big fandom was probably The X-Files when they were still on their first run! Before that, I had a bunch of bands/singers etc. but fandom was much much different before the internet was a really common thing. Wow. That was nearly 25 years ago now! LOL

Agreed on the current writing, and I have some issues with the way the books were written... but the universe itself is still a wonderful, beautiful one I still occasionally dip into. :)