Serious Business: Although he can be fun and amusing, he truly cares about music, and doesn't appreciate people treating the show like a joke; telling off Rick Rowling, who came in and told stupid, unfunny jokes solely to further his "acting career", proved this.
The Runner Up Takes It All: He was the first contestant from the season to find success, enjoying moderate sales and success in the Country genre and opening for Sugarland on their tour immediately after the end of the season.
Shocking Elimination: Definitely this for Season 9, with both the judges and David Letterman baffled at her elimination.
Could technically be called the most important, at least in terms of effect, with the episode immediately after her elimination being the least viewed episode in American Idol history.
The Runner Up Takes It All: It took a little a while, but she seems poised to do this with her new band Doubtful Guest, which is comprised of members of Everclear, Godsmack, Third Eye Blind, Fuel, and Candlebox, and is sponsored by Hansen.
Runner Up Takes It All: It took several years, and she's not even famous as a singer, but now as one of the stars of MTV's Faking It, she's in the only person from the season that anyone knows.
Vocal Evolution: Started the season with strong vocals that possibly rivals runner-up Jessica. But as the week goes on, her vocals becomes weaker. She managed to recover before a subpar performance did her in in the top 4
Ascended Extra/Born Lucky: He was only accompanying his sister during auditions for moral support. The judges, knowing how talented he is during his stint in season 10, called him and made him audition on the spot. We know the rest.
Ascended Fanboy: Full Stop. Sang both Daughtry's What About Now and Dave Cook's Permanent, showing he has an affinty for past contestants. Also consider he's now writing songs with Lifehouse's Jason Wade, who's song Everything he sang, as well as Daughtry.
Heterosexual Life-Partners: With Phillip Phillips. They did both group numbers in Hollywood and Vegas together and were inseparable until Heejun left the show.
Mood Whiplash: After a few weeks of crooning ballads, Heejun appears to being the same thing. He starts crooning a snoozy, painfully slow ballad yet again...then suddenly tells the band (they'd planned this ahead of time), "Stop! This is too slow for me! AND I WANNA DANCE !" and rips off his tuxedo, revealing more casual clothes underneath, and starts belting Billy Joel's "Movin' Out." Doubles as a Crowning Moment of Awesome.
Fight Magnet: Well, more of an Argument Magnet, during the Hollywood rounds; she went through two groups and had issues in both, causing some fans to see her as a Jerkass who can't work with others. But in reality, she remained professional and respectful (albeit a little frustrated here and there) through both. This culminated after her group finally performed, where the mother of the only eliminated contestant from the group blamed Jessica, and this actually brought poor Jessica to tears. She even lampshades this:
"Drama seems to follow me wherever I go..."
Mr. Fanservice: The show seemed to be pimping him as this; the judges rarely made a comment without mentioning "the ladies".