In its 15 seasons, “American Idol” has seen many singers come and go, many without much fanfare as the exited the world of reality TV. But some contestants actually had staying power. Here’s a look at the five biggest stars to emerge from the singing competition.

1. Kelly Clarkson signed immediately with record label RCA after winning the first season of “Idol” in 2002. Her single “A Moment Like This” topped the Billboard Hot 100 in 2002, and she was the runner-up of “World  Idol” the following year. Clarkson’s album “Stronger” won the Grammy for Pop Vocal Album. She won this award in 2006 and 2013. She returned as a guest on “Idol’s” 15th season, bringing the judges and audience to tears with her performance of “Piece by Piece,” which detailed her abandonment by her father, as well as her husband’s love for her and their daughter.

2. In 2004, Jennifer Hudson started getting attention as a season 3 finalist. She came in 7th place. Two years later, she signed with Arista Records. Not only has Hudson won a Grammy, she took home an Oscar in 2007 for her role as Effie White in “Dreamgirls.”

3. Another famous Idoler is country singer Carrie Underwood. She rose to fame as the winner of season 4 in 2005. Underwood signed with Arista Records and went on to win numerous awards, including an American Music Award for Artist of the Year in 2007 and Entertainer of the Year at the Academy of Country Music Awards in 2009.
4. Season 6 contestant Jordin Sparks became the youngest winner in the series’ history in 2007 at age 17. In February 2012, “Billboard” ranked Sparks at No. 92 on the list of the “100 Greatest Women in Music.” Like Hudson, Sparks also pursued acting. In 2012, she came out with a movie called “Sparkle,” followed by roles in “The Inevitable Defeat of Mister and Pete,” “Left Behind” and “The Grace of Jake.”
5. Kris Allen was the winner of season 8 in 2009. Allen’s “Idol” song, “No boundaries” and his version of “Heartless” by Kanye West both hit the top 20 of the Billboard Hot 100. Allen signed with record labels Jive (2009-2011), 19 (2009-2012), RCA (2011-2012) and his recent, DogBear Records (2014).