I watched the first probably 4 seasons of SP somewhat religiously and after that it was very infrequent. I think the last episodes I watched was the "Crap People" episode and the Smug/Smog episode, and never attempted to watch it again. I like to get my witty social commentary from Colbert
Maybe South Park has "gotten better with age" and gotten "smarter" but when I think South Park the first thing that comes to mind is anal probes, how many times is Kenny going to die, and gerbils going into a mans anus.
There is nothing funnier than when Family Guy does a Star Wars reference. Last season of FG was gold, this season hasn't really done it for me.