http://whatculture.com/tv/every-season-of-south-park-ranked.php

Nineteen seasons is a long time for a TV show, but South Park isn't slowing down. If anything, it's finally peaking again.

They ranked Season 10 at the best, but I think that season was its worst!

"Cartoon Wars" and "Make Love, Not Warcraft" were its best, but it has VERY bad episodes like "A Million Little Fibers" and "Stanley's Cup" which in all South Park lists are the worst ever!

I would say Season 7 is their best because Kenny returns and the show is back to its sensation!

The show really hit its stride between Season 5 and 10, IMO. That's where most of the memorable episodes of South Park fall.

Season 19 wasn't bad however.