I've posted some of my thoughts on this in the Cheeky Muppet Moments thread, but here's one (and this is technically off-topic):
In the Pirates of the Care-to-be-readin' episode of Sesame Street, one of the characters makes a statement that is something like "No chance in L."
But, yeah, The Great Muppet Caper and Muppet Treasure Island are filled with jokes I didn't get as a kid. Such as this painful, hidden gem from TGMC:
Scooter: Popcorn! Popcorn! (Looks at chicken) Popcorn, chicken?
HA! Popcorn chicken! That's hillarious! ... Well, not really, but it is the first time you realize it's supposed to be a joke.