One of the best sequences is:
Kyle - "I think I know the answer Mr. Garrison"
Cartman - "*mocks Kyle*"
Kyle - "Shut up fat boy"
Cartman - "Dont call me fat you ****ing jew"
Mr.Garrison - "Eric, Did you just say the F-word?"
Cartman - "...Jew?"
Kyle - "No, hes talking about ****, you cant **** in school you ****ing fat ***"
Mr.Garrison - "Kyle!"
Cartman - "Why the **** not?"
Mr.Garrison - "Eric!"
Stan - "Dude, you just said **** again!"
Mr.Garrison - "Stanly!"
Kenny - "*muffled* ****"
Mr.Garrison - "Kenny!"
Cartman - "Whats the big ****in deal? It doesnt hurt anybody. **** ****ity **** **** ****..."
Mr.Garrison - "How would you like to see the school conselor?!"
Cartman - "How would you like to **** my balls?"
*Class gasps*
Mr.Garrison - "What did you just say?!?!"
Cartman - "uh uh, I'm sorry, what I meant to say was...*pulls out megaphone*...'How would you like to **** my balls, Mr.Garrison'"
Stan - "Holy shit dude..."