Futurama, tbh.

The Simpsons loses marks for recent seasons, but they really do have some classics from the '90s. I mean genuine gold that's worthy of governmental preservation. I can't really think of much Family Guy that's on that level.

But yeah, I'd have to go with The Simpsons here. There really is nothing funnier than stuff like

Homer: Hello, my name is Mr. Burns. I believe you have a letter for me.
Postal Worker: Okay, Mr. Burns, uh, what's your first name?
Homer: ...I don't know.

Or

Homer: TRAMAPOLINE! TRAMBAPOLINE! JSAVA!