Korn Gets Groovy (1999)
"Korn's Groovy Pirate Ghost Mystery" turns the nu-metal stars into the "Scooby Doo" gang, as they invade South Park to chase down pirate ghosts and learn life lessons. Bassist Fieldy is hilariously turned into the Velma of the group, with the obligatory scene in which he can't find his glasses while pirate ghosts (or is it ghost pirates?) are approaching.
Diddy Says 'Vote or Die' (2004)
Luckily, Diddy's 2004 "Vote or Die" campaign wasn't literal, or else it would have looked something like this Season 8 episode. The rapper goes door-to-door threatening people who don't understand the importance of voting, brandishing a handgun in their faces and rapping, "Get out there and vote, or I will motherf--king kill you."
Bono's Big Load (2007)
What's more insulting: the depiction of Bono as an opportunist who dances around impoverished countries singing "Vertigo" to himself? Or the depiction of Bono as a giant piece of crap -- literally? Either way, the "South Park" creators clearly aren't fans of the U2 singer and humanitarian, and give him a skewering reminiscent of the "Mecha-Streisand" episode.