The 20 greatest performances on 'American Idol' of all time

Of course Kelly Clarkson's on this list. How could she not be? She was, after all, the first ever "American Idol" winner, going on to amass great fame and fortune. If we had to pick from all her "Idol" performances, the one that shined the most was her rendition of Aretha Franklin's "Natural Woman."

As part of the season two finale, Clay Aiken chose to perform Simon & Garfunkel's "Bridge Over Troubled Water," taking the hymnal-like nature of the song a step further by singing it with a gospel choir. 

After eventual season three winner Fantasia Barrino was done singing the George Gershwin classic "Summertime," judge Randy Jackson said it was the best performance he'd ever seen on "American Idol." Fantasia's rendition wasn't as good as Billie Holiday's or Ella Fitzgerald's, but it was damn close. 

Jennifer Hudson didn't make it past the Top 7 stage of season three, but after she performed "Circle of Life" from "The Lion King" during Elton John Week, the whole world pretty much knew she was going to be a star. Hudson would of course go on to win an Oscar and a Golden Globe for Best Supporting Actress for her role in "Dreamgirls."

It's hard to believe now, but Carrie Underwood, who's gone on to sell millions of records, was at one point unwilling to come out of her shell. That all changed when she performed Heart's "Alone" in season four. The shy country singer stepped into the limelight, and she hasn't looked back since. Underwood, by the way, would be crowned as that year's idol.

It's easy to want to hate on Bo Bice. His duosyllabic and alliterative name, his wannabe messianic hair, and the look of intensity on his face may all cause involuntary eye rolls. But the dude can sing, as evidenced by his spectacular rendition of Badlands' "In A Dream." Credit where credit is due.

Chris Daughtry didn't make it past the top four in season five, but by that point, he had already proven he could be a huge rock star thanks in large part to his rendition of Fuel's "Hemorrhage (In My Hands)." Sure enough, RCA Records gave him a deal after he got booted from the show. 

Katharine McPhee should've won season five of "Idol." Her rendition of "Over the Rainbow" from "The Wizard of Oz" is one of the show's all-time greatest. It didn't matter, though. McPhee has since gone on to become a television star. 

How do you sing a Bon Jovi song and not make it sound like you're doing karaoke? By adding beatboxing to it, of course. That's what season six runner-up Blake Lewis did to "You Give Love A Bad Name," and honestly, we kind of wish Bon Jovi would record that version of his classic as well.

No disrespect to Blake Lewis or Jordin Sparks—the runner-up and winner of season six, respectively—but the fact that Melinda Doolittle wasn't named "American Idol"  that year was one of the biggest robberies in the show's history. Her standout performance came early on, when she sang the classic "My Funny Valentine."

Jordin Sparks won season six of "American Idol" solely on the strength of her renditions of Ben E. King's "I (Who Have Nothing)"— she performed it twice, once during "British Invasion" Week, and during "Top 3" week. 

The first time David Archuleta performed John Lennon's "Imagine" on "American Idol"  during season seven, Randy Jackson said it was one of the best vocal performances in the show's history. Paula Abdul followed up that compliment with one of her own, claiming it was one of the most moving performances she's ever heard. Yes, it was that good.

There are two types of "American Idol" performances: those that take a song and completely transform it into something else, and those that do it justice by sticking to the original as much as possible. Adam Lambert did both (he's the only person on this list twice). His performance of Johnny Cash's "Ring of Fire" falls into the first category, morphing the iconic country song into a sultry whisper by trading in the mariachi horns for a sitar.

When it came to his performance of Tears for Fears' "Mad World," Adam Lambert kept the vulnerability of the song, being as faithful to the original as much as possible. Lambert didn't win season 8—he was the runner-up—but he certainly deserves to have two performances on this list.

Kudos to Kris Allen for thinking he could make a Kanye West song better. Ultimately he didn't—how could he without a Roland TR-808 backing him?—but his rendition of "Heartless" was refreshing enough to propel him to eventual victory in season 8. 

Haley Reinhart finished in third during season 10. Half the time, she was facing elimination. The other half, she was among the best. Her standout performance that year came during Elton John week, delivering a version of "Bennie and the Jets" that perfectly matched her vocals with the pounding of the piano. 

There's never going to be another Whitney Houston, and there will never be another person who will sing "I Will Always Love You" better than she did. But if you close your eyes while listening to Jessica Sanchez's version of that song, you can almost hear Whitney. 

With a name like Phillip Phillips, you really need to have some top notch talent to make people forget how silly your name sounds. Double-P was more than qualified. That was most apparent during his season 11 performance of Damien Rice's "Volcano." Phillip Phillips would go on to win the whole shebang that year.

With apologies to the diehards and Robert Smith, The Cure's "Lovesong"  is a beautiful song that could be better served by vocals with some actual range. Candice Glover most definitely fits the bill, proving it in season 12 when she performed the song. After she was done, she got a standing ovation and Randy Jackson dubbed it as one of the show's best performances ever.

"I Put A Spell On You" is inherently an intoxicating song—Screamin' Jay Hawkins originally envisioned the song as a ballad, but he and the band were obliterated, and the rest is history. That same feeling of visceral recklessness was present in Quentin Alexander's performance of the song in Season 14.