So many good sequels to choose from. Log Horizon is my #1, but I'm also really looking forward to Slime, Dr. Stone, and Re: Zero.
Promised Neverland and Bestars will probably be good as well, but I already finished both manga.
Attack on Titan really went downhill towards the end, but maybe the anime will do a better job with the story than the manga did.
Hell, these are only the sequels, we still have Kumo, Horimiya, Mushoku Tensei... I'm going to seriously need to clear some time in my schedule this season.