Family Guy: When Peter Griffin has a flashback of him killing Hanson with a shotgun.
Becker: When he unknowingly hires that sex-addict as his nurse, and finds her gettin' it on with one of his patients.
The Simpsons: When Homer becomes the mascot for the local baseball team. Lisa's encounter with Bleeding Gums Murphy is a close second.
Chappelle's Show Season 1 Episode 6: When that White Guy gets stuck in a Real World Episode with his roommies all being black.
I Love Lucy: Vitameatavegamin. Amazingly funny.