What: The debut of the character Cheese on the Foster’s Home for Imaginary Friends episode “Mac Daddy.”

Why: The funniest of the new generation of Cartoon Network series, Foster’s Home for Imaginary Friends depicts a world where children’s imaginary friends are real, and face a real problem. When the child gets too old for such things, the friend must be put up for adoption. Enter Foster’s, a cash-strapped, overcrowded, rabbit-run foster house for all manner of strange beings who just want a kid to love them. The series doesn’t shy away from the emotional charge of this issue, as in the episode “Mac Daddy,” when the protagonist Mac apparently dreams up a new imaginary friend named Cheese, and his original imaginary friend Bloo is not happy. Cheese is the baby brother you wish you didn’t have, being annoying and demanding and in constant need of help. Plus, he’s just about the funniest thing on earth.

Impact: Cheese was a one-shot character who came back for at least three other episodes and a bunch of promos when the producers figured out they’d created a great character. The other episodes with Cheese aren’t quite as classic, but they’re still darn good watching.

Personal Connection: “Mac Daddy” is entirely formed out of quotable material. Evon and I constantly parrot the lines “Now you’re a horsey!” and “I liiiiike chocolate milk” and “Floor tastes funny,” usually to the blank stares of our friends. By the way, my imaginary friend was named Redwing.

Other Contenders: And now here’s something I hope you’ll really like: Bullwinkle tries to pull a rabbit out of his hat; two dangerous damsels go all Thelma and Louise in the “Harley and Ivy” episode of Batman: The Animated Series; Bugs Bunny steals an Eludium PU-36 Explosive Space Modulator from Marvin the Martian in “Hare-way to the Stars”; the Animaniacs episode which asks the question “Would you like to take a survey?”; The Simpsons’ episode “Marge vs. the Monorail,” and since I can’t find a clip, please enjoy this highly topical version of “The Monorail Song.”