Family guy used to have some pretty good moments, but the recent seasons have become too formulaic with the goofy non-sequitors and dragging-on-forever running gags. Yeah, it's very sophomoric, and depends heavily on pop culture references, but when done well the shock value can be really entertaining. Family guy is pretty hit or miss in that sense. More miss than hit recently.
For animated shows, I like Futurama best - lots of witty science jokes, intelligent humor, and generally well thought out character and plot development. It's like all the good writing ability from the early seasons of The Simpsons transferred over to Futurama, and the show took a decidedly more intelligent approach.
I also enjoy South Park quite a lot, which, while often even more offensive than Family Guy, is an equal opportunity offender. They pick on liberals, conservatives, people of every religion and every ethnicity. They point out hypocrisies and the ridiculousness of our society in sometimes incredibly subtle ways. The show is, in my mind, at its best when it's doing social commentary, where it often points out how idiotic people on BOTH sides of the arguments are, by blindly following an ideology rather than thinking for themselves. Anything that blasts the goofy partisan walls the politicians and media have built up to keep us as a people divided is OK by me.
Wow, that was a lot of commentary for a thread about a cartoon fat guy singing an old song. Have you guys heard about the bird?