Having read fanfiction obsessively as a dorky high schooler, I have thankfully overcome it to obsess over fantasy books and Netflix, now, instead. I check my favorited stories once or twice a year for updates, now that I remember my password again, but don't search for new stories. Partly because I'm now a professional copy editor and wading through too much murder of the English language to find a good story would likely send me into convulsions.
I used to read Gundam Wing, Inuyasha, and X-Men Evolution regularly, as well as Roswell and Slayers occasionally. Good fanfiction seems to come best from those stories that leave a lot of potential unfulfilled.
Thank you to all the authors who put so much time and effort into truly getting to know beloved characters and filling in the gaps or exploring new worlds with them.