A lot of the anime-related communities have consolidated over time to the ani.social instance. There are historical reasons for this (largely due to hostility from the ml admins), and if you want a brief history for just the general anime community, I previously wrote a post here.
That being said, the ani.social instance has been growing with new communities being added. Here are the more active ones:
General Communities
Series-Specific Communities
- [email protected] - Delicious in Dungeon community
- [email protected] - Frieren: Beyond Journey's End community
- [email protected] - My Deer Friend Nokotan community (currently airing show)
- [email protected] - Dan Da Dan community (show airs this fall)
- [email protected] - Dragonball community
Misc.
- [email protected] - Very new community just started by @[email protected] about vocaloids. Check it out!
- [email protected] - Community to discuss and share videos from and about vtubers
- [email protected] - Community about Japanese voice actors behind the scenes