Season 19 is the worst season of South Park
I know this is subjective, but I grew up with South Park, and I honestly think Season 19 is garbage. It actually got to the point where I stopped watching it.
South Park started as a show about four friends. Even though there often was a sociopolitical message, it was, first and foremost, a show about kids dicking around and getting into funny situations. There are no longer kids-being-kids plotlines. The characters (and, in turn, the show's charm) have gave way entirely to the message. They are really just vehicles now for what Matt and Trey are trying to tell us, sometimes to the extent where they deliver monologues without any real context (thinking Jimmy in the ad episode). I miss episodes where they built treehouses, played games, had crazy schemes, and did other normal kid things. There has always been that South Park twist with the celebrity cameos and the message weaved in, but Season 19 is just the message, episode after episode, being hammered into my head, and it's rarely funny.
I understand that there's a meta-aspect to this, that perhaps Matt and Trey are saying society is so PC now that it's preventing people like them from being funny (hence Cartman's transformation from a devious sadist to a whiny bitch). But the resulting season felt very overt, very forced, and was seldom funny.
In my opinion, the peak of South Park was seasons 3-10, episodes like Scott Tenorman Must Die, Good Times With Weapons, Casa Bonita, ManBearPig, the LOTR episode. It just pains me that people think Season 19 is one of the best, because the show has deviated so far from what made it work. As someone who has been a fan for over 10 years (and has watched back to season 1 even though I was only 5 when it first aired), I just really think South Park has jumped the shark.