I didn't appreciate King of the Hill when it first aired but it definitely grew on me over the years. What animated shows are still good?
Bob's Burgers is still good.
American Dad has become increasingly daring and unhinged as the years have gone along. It was a pretty shit show in the early years and it got better as MacFarlane became less involved (he used to run the whole show, but now he just does voicework and occasionally pitches ideas while other people do the day to day showrunning).
Family Guy is exactly the same as it ever was. So mostly shit with occasionally good gags; I only ever end up watching it because I'm too lazy to change the channel after Bob's Burgers.
Futurama has jumped the shark several times over and is a sad shell of its former self. Don't bother even trying.
No need to rehash how shit the Simpsons has been for a long time.
South Park recently had some pretty lazy seasons and some tryhard over serialized seasons, but this whole business with Paramount trying to stiff them and then sucking Trump's dick has fired Matt and Trey up and the most recent season premiere was hilarious.
The Beavis and Butt-Head revival is fantastic. No reservations, it's as good as you could possibly ask for.
Rick and Morty has had a strong couple of seasons after all the dust with the Roilland shit settled. They went off the rails for a couple years there but they pulled out of it. They are committed to actually growing their characters and the show has benefitted from that.
If you haven't seen Common Side Effects, check that one out. It's from Mike Judge's studio and he does some voicework on it, but he's not behind the creative. It's a serialized drama, not a sitcom like the others, but it's really good. A lot of the people who made it came from the canceled one-season HBO show Scavenger's Reign, which is a really unique show that follows people on a very alien world. Definitely check that one out.
I've recommended Undone a billion times and I'll keep doing it, if you haven't seen that one it should top the list.