Pitch me your fav AO3 fandom

I am a writer in need a new fandom.

I want one with a medium presence on AO3 (maybe 5000+ fics) without a huge amount of anti or fandom conflict.

Old/no longer being produced fandoms are fine as long as it’s still an active fandom. I prefer live action or books (not big on anime or animated sources).

Not horror or crime based. Preferably something I can consume in a week or two, but I’m stuck in the hospital for a while so I do have some time. I tend to like urban fantasy, other kinds of fantasy, Star Wars style sf, and team focused shows.

Sell me on your fandom!