Simpsons, easily. The first 3 seasons of FG were great, but I haven't enjoyed many of the new ones. They're trying way too hard, and the jokes/flashbacks are getting predictable, and in some cases, quite lame. It took 10 years for that to happen to Simpsons. Not to mention a lot of the great stuff from FG was stolen from Simpsons. And if that's enough, Simpsons uses it's recurring characters so much better than FG.
Seasons 3-7 of Simpsons > any other animated show.