I really don't understand all the love for this episode. A bit too disturbing for my liking.
It's like a culmination of all Cartman's stupid antics up until that point. Stuff like the schemeing to get $10 Million, the period, all that. It seems like it's just going to be a formulaic "Cartman does something stupid and does more stupid stuff throughout the episode" (albeit a lot of it is funnier than all the other ones like that) type episodes, and then the whole thing takes a SHARP left turn and Cartman is an evil genius, if just for one episode, and has been manipulating everyone the whole time. The whole thing is just fantastically played out. It's my favorite episode of this show and probably one of my favorite episodes of ANY show.
EDIT: And how can you not love "Ha ha ha ha ha ha, I made you eat your parents!"?
But yeah, I can see how tricking someone into eating their parents in revenge for being tricked into buying said person's pubic hair might be a little off-putting.