American Idol had 15 seasons until it returned in 2018, so there have been many winners. But winning isn't all it's cracked up to be. Just because American Idol's 19 winners won one of the biggest singing competitions in the world doesn't mean they became famous after their time on the show.

Out of all the winners, some are way more famous and successful than others. Only three of the 19 have come out on top. Kelly Clarkson, of course, has had an impeccable career since winning. So has Carried Underwood. She's changed so much since winning and is now worth a whopping $140 million. Jordan Sparks has had success in music and acting too.

Ironically, some runner-ups on the show have made it even bigger than the rest of the winners. We still can't believe Jennifer Hudson didn't win because she's had an impressive singing and acting career. There's also Adam Lambert, who's singing for Queen now. So it just goes to show that the real winners always shine through.

But where have the forgotten winners gone? And more interestingly, who wins the title of being the most unsuccessful America Idol winner?

Season 12 Will Live On In American Idol Infamy

It's hard to keep track of all 19 of American Idol's winners. Some of them we don't even remember winning, so we're definitely not sure what they're up to today. But fans know exactly who's the worst winner.

The site Gold Derby ranked all 19 winners, not by net worth, but "from worst to best based on their record sales, concert revenues, awards success and overall impact on the music industry." The person they ranked at the top of the list is season 12 winner Candice Glover, who won singing "I Am Beautiful" in 2013.

Related: 'American Idol': Fans Upset Over Chayce Beckham Win

All the reasoning the site gives as to how she got placed at worst is, "Her solo studio album, Music Speaks, was delayed and released a year after her win to modest success," which is fair.

Glover is the only winner to have auditioned for the show three times, and maybe there was a reason why she didn't get through the first couple of tries. She auditioned in seasons nine, 11, and of course, 12.

During her first audition in season nine, Simon told her he couldn't see her being much more than a lounge singer. In season 11, she advanced relatively far but was cut. When she auditioned in season 12, Randy Jackson and Marish Carey called her the best voice they'd seen so far.

During her time in season 12, she had some standing ovations for renditions of The Cure’s "Lovesong," Dionne Warwick’s "Don’t Make Me Over," and Ben E. King’s "I (Who Have Nothing)."

Related: Here's What The First 10 'American Idol' Winners Are Up To Now

After winning, she released Music Speaks, and it was pushed back; after her winning song "I Am Beautiful," only made it to No. 33 on the R&B charts. But by then, she was completely forgotten about as a new American Idol winner was paving their own way.

"So long story short: we delayed the album, and one of the times that we decided to delay it, Interscope, which was the label that you get signed to when you win, was not in contact with iTunes at the time or 19 Entertainment, who was the management company," she told NBC News.

"There was a communication issue, and so my album came out by accident, actually. And everybody that pre-ordered my album the night of my win got a blank album to their phones — a complete blank album. iTunes made a statement and said that they never experienced that before and they were so sorry and everything. But with that being said, people missed out the opportunity to get my actual album when it did come out the following year. So my album came out and didn’t get a really big response."

All of this made her go on a hiatus and completely cut out social media. "That definitely affected me … and by me not really posting on social media and stuff, definitely when you're not letting people know what you do every day, you kind of lose that audience," she said.

Related: Everything David Cook Has Been Up To Since Winning 'American Idol'

Glover doesn't regret her hiatus, though. She took time out to grow, cut ties with the record company, and release some songs via her Soundcloud account.

In 2017, she released the singles "My Mistake" and starred in the Broadway musical Home for the Holidays, joining other singing competition winners like Bianca Ryan of NBC’s America’s Got Talent and Josh Kaufman of The Voice.” She called her Broadway experience a blessing.

Ironically she was supposed to star in a jazz-themed Broadway production, but plans fell through, which is kind of good when you think about it. She didn't live up to Simon's expectations that she'd end up in a jazz lounge.

"It definitely feels like an accomplishment to finally make it to Broadway," she said. "People don't really know, but the very next day after I won American Idol, I was supposed to do it, but I was feeling very down about that because I really wanted to be on Broadway."

In 2018, she released another single called "Break Me." So even though she's not worth $140 million like Carrie Underwood or has a talk show like Kelly Clarkson, Glover is successful in her own right. She has to keep working at it.

Next: Everything Ruben Studdard Has Done Since 'American Idol'