I always thought it was just crude humour as a kid.
Once I realized how true their jokes are, it got so good.
I just watched Child Abduction Isn't Funny and The Return of the Lord of the Rings to the Two Towers. Both were hilare!
MONGORIANS! Keep breaking down my CHITTY WALL!
And when Butters is watching Back Door Sluts 9, so funny.
Im sure theres a ton of other episodes I'm just not thinking of right now.
I love the Lord of the Rings Episode! Especially the part when Jimmy is trying to tell the parents the kids went to the video store and Randy, Stephen and Gerald are all trying to finish his sentence.
Jimmy: They went to the video st- the video st-
Randy: The video sandwich?
Stephen: The video staples, they went to the video staples.
Jimmy: No! The video store, retards!