I'd have to say the thing were they are all sitting in the courthouse, saying "Oh no!" one by one, and the kool-aid man bursts in and is like "Oh Yeah!!!".


or


"It's a boy, Mrs. Griffin"

"I'm afraid the accident has permanently hampered his motor skills, Mrs. Griffin"

"I'm afraid he's going to have to repeat the fourth grade, Mrs. Griffin"

"I'm afraid he's going to have to repeat the fourth grade, Mrs. Griffin"

"Congratulations, Mr. Griffin; you've passed the fourth grade!"

"Oh boy that's great. See I'm going on a hunting trip with my son, Chris"

When he turned the house into a puppet and when he made a fort out of pillows on an airplane (both from the same episode, I believe).

When the Grim Reaper was lame and Chris had to take over.

i like the one where they get superpowers and meg wants to meet n'sync then peter turns into britney spears and right before he goes in lance and jc are sitting there and lance says in a really gay voice "Do you wanna split a toblerone?" then Jc says (once again in a gay voice "Ya i think i do, Choo choo next stop my thinghs"