iCarly: The episode "iRocked the Vote" featured Season 7 runner-up David Archuletta (playing himself) winning America Sings against Wade Collins, who turns out to be a massive prick who tried to gain sympathy votes with a sob story about his mother being sick. Collins is an unflattering (and borderline scathing) caricature of that season's winner, David Cook, who frequently talked about his brother Adam's battle with brain cancer (which he lost just a few months after the episode premiered).
The Fairly OddParents!: The main plot of "Fairy Idol", in which fairies (and Norm the Genie) compete to replace Cosmo and Wanda after they quit their jobs, is a parody of the show.
Family Guy: A cutaway from "Lois Kills Stewie" involves Stewie auditioning before Simon, Paula and Randy, all of whom provide their own voices.
Robot Chicken: A sketch from "The Deep End" features Ryan Seacrest hosting Zombie Idol, whose contestants are the reanimated corpses of famous musicians.
In "A Star is Torn", the concept and logo for the Krusty's Li'l Starmaker singing contest is a parody of American Idol (which legal claimsthey've never even heard of). To top it off, Season 3 champion Fantasia Barrino guest-stars as a rival of Lisa's.
In "Judge Me Tender", Moe becomes such a popular contest judge that he's chosen to co-judge the new season of American Idol.
