It's been about 2 years since I've watched a Family Guy episode. After the Southpark episode that made fun of them, I could never get past how awful the show really was. I don't know if I can say the same about seasons 1-4, as I still find those funny, but as that picture above shows, the characters have changed to be so one-dimensional.
Southpark is falling into the same hole, but they are doing it a lot more slowly, so I can tolerate it a little more. Also, none of the cast plays the retard in Southpark, so it doesn't seem like they are running out of ideas as fast. Personally, I'd love to see Southpark canceled and have them move to weekly shorts over the internet like Yahtzee. I think Southpark can still thrive in that form.
And some one mentioned American Dad. HELL YES! It seems like the moment Family Guy started getting dry and retarded, American Dad started getting better and better until it was awesome. I have a feeling like it's reached its peak though, and I kinda wish that the recent rapture episode was the series finale. Kill it while it's still fresh so we don't have to remember the crap that follows.