The Simpsons might be the greatest and longest running, but I haven’t watched it regularly in 15 or so year, and I’m not sure why because I’m sure it’s still pretty good. Homer has always been tremendous. I tried to watch some Beavis and Butthead a while back and frankly it just doesn’t hold up.
South Park is probably my favorite and King of the Hill would be a close second, for Dale Gribble alone. Rick and Morty is pretty good too and a couple years ago I had an Adventure Time phase, granted I was smoking a lot more dope back then.
Honorable Mention: American Dad