Jellyfin if you do not like being spied on by your self hosted media library. Plex if you do like being spied on by your self hosted media library.

Also - Plex if you want Audiobooks, because the app Prologue is 🔥

I only still have a plex server running for audiobook support with the app Prologue. Everything else is happy in Jellyfin and and has been rock solid. Plex went way to corporate and it creeped me out.