I think, with a couple notable exceptions, this has been a very strong season. Cock magic, Oculus rift, Lorde, Freemium gaming, a lot of strong episodes this year.
I think South Park's best period was seasons 3-8. After that it kind of dwindled into medocrity where a lot of the episodes were either disgusting for the sake of disgusting, they leaned on things Matt & Trey think are funny and nobody else does, or they just followed the formula of previous episodes. I think the last two seasons are the funniest the show has been since season 8.
There hasn't been anything this season nearly as stupid as Human Centipad, the Japanese food restaurant, the episode where Michael Jackson possessed Ike, Randy trying to break a pooping record. Since there were fewer episodes this season I think it let them put more effort into their good ideas instead of spreading them out across their incredibly stupid ones.