You just said whats your favorite, not if it's relevent. The Simpsons was a great show intill they fucked it up.
Family Guy,The Ren and Stimpy show and the Clerks animated series was good too but it was like 5 episodes only.
King of the Hill, Futurama, The Simpsons. I can confidently say that it never has deteriorated. They may run out of ideas, but that's because they've literally done absolutely everything, which is an amazing achievement.
Don't get me wrong its just that the old episodes are so much better than the new one because like you said they are just running out of ideas they have been on TV since 1989. The Simpsons is the longest-running American sitcom and the longest-running American animated program.
Adventure Time, Regular show, the amazing world of gumball, south park, Futurama, Tom and Jerry, and the Looney tunes show.