Specifically, the discussion about the levels of humor in cartoons. I throw the gauntlet out there for people come up with the most subtle references they've ever heard in cartoons:
Here's my two to start:
Challenger. Hoo Boy, you've got train coming? - Boris Badenov
But Brain, Snobol for Windows? - Pinky
Here are a few:
Ah phooey! -Donald Duck
Eh? What's up, Doc? - Bugs Bunny
Jane! Stop this crazy thing. - George Jetson
Screw you guys, I'm going home. - Eric Cartman
Fred Flintstone (to Barney Rubble, after Barney misinterprets Fred's instructions): How many heads do you have?
Barney: Two.
The above occurred in only one episode IIRC.
Bullwinkle: <i>Hey Rocky, watch me pull a rabbit out of my hat!</i>
There was an episode of 'Sesame Street' where the cast flew to Hawaii, and the interaction between Oscar the Grouch and the woman at the airport metal detector is full of obvious adult humor.