Simon Cowell's 9 Most Memorable 'American Idol' Moments

"I went back home to watch it. It wasn't quite so clear cut as we called it. And in fact, David, I will take this opportunity to apologize, because I think I was verging on disrespectful with you, and I don't think you deserved that," Cowell told a stunned Cook.

Good thing, too, since Cook was declared the winner after that.

'Bigger Stage' for Cowell

Some of Cowell's most scathing remarks came during the audition rounds. One of the the most memorable was during the casting of Season 5.

After giving plus-size contestant Mandisa a golden ticket to Hollywood, Cowell couldn't resist a quip after she left the room. "Do we have a bigger stage this year?" he said.

"She's like Frenchie," Abdul added, referring to another former plus-size contender.

"Forget Frenchie, she's like France," Simon said.

Later, Mandisa, who dropped 75 pounds after "Idol," admitted seeing Cowell's comments was her "worst fear come true."

Cowell Hugs a Contestant

Cowell wasn't always so mean. In recent years, Mr. Mean has even gotten a little soft. Blogger Santilli chalks some of that up to boredom. "He's going through the motions," she said. "I'm going to miss Simon at the top game."

But even a softer Cowell is memorable to watch. Last season, when Renaldo LaPuz, from Reno, Nevada, auditioned for the judges, he wore a white suit, silver cape and white feather that that bore Cowell's name.

As expected he sounded awful, but his original song, "We're Brothers Forever," touched something in Cowell, who embraced him before letting him down easy.

"You are very entertaining. ... I actually like you," he told LaPuz, reducing the 44-year-old to tears.