The 15th and final season of "American Idol" begins tonight, and there are so many incredible moments and so much talent to look back on over the years. Some of the most popular names in music began on "Idol," and they have the original singing competition show to thank for their successful career.

Ever since superstar Kelly Clarkson won the first season, many talented artists have followed in her footsteps, and several of the most successful names weren't even winners.

"I've seen what 'Idol' does," Judge Harry Connick Jr. told HNGN exclusively. "We have 'Idol' to thank for a lot of great talent. I'm not sure we'd know about Kelly Clarkson or Fantasia, Jennifer Hudson or Adam Lambert without it."

Here are what we believe are the 10 successful "American Idol" contestants we've seen since the series first aired in 2002...

Kelly Clarkson

Clarkson really set the bar high for every contestant to follow. After winning the very first season of "American Idol," and arguably having the most successful career of all, she's become a name that everybody knows. Clarkson's debut single "A Moment Like This," which she performed during the finale, topped the Billboard Hot 100 and became the best-selling single of 2002. Her 2003 debut album "Thankful" was number one on the Billboard 200 and sold over 4.5 million copies worldwide. Since then, she's released six more studio albums. Her latest, "Piece by Piece," was released earlier this year and was her third to debut at the top of the Billboard 200 chart. Throughout her career, she has won three Grammys, three MTV VMAs, twelve Billboard Music Awards, four American Music Awards and two Academy of Country Music Awards.

Carrie Underwood

Underwood rose to fame after she won the fourth season in 2005. She became one of the most popular country singers to come out of the competition and has set and broken several records throughout her career. She released her debut album "Some Hearts" the same year she won and it became the fastest selling debut country album in history, the best-selling solo female debut album in country music history and the best-selling country album in the last 10 years. She is currently working on her fifth studio album, which will be called "Storyteller." She has won seven Grammys, seventeen Billboard Music Awards, eleven Academy of Country Music Awards and nine American Music Awards.

"It's very bittersweet for 'American Idol' to no longer be on TV after this season," Underwood told In Style back in November. "15 seasons, 15 years is an incredible amount of time for any television show to be running that successfully. So I feel like they should all be so, so, so proud. And I of course am thankful for that show because I wouldn't be standing here without it. It'll be fun to see the last season, though. I think they're going to go out with a bang. Again, it gave people like me a chance. It's changed the music industry, changed the entertainment world, and I'm beyond grateful for it."

Jordin Sparks

Sparks won the sixth season of "Idol" in 2007 when she was just 17 years old, becoming the youngest winner in the series' history. Her self-titled debut album was released that same year and has sold over two million copies worldwide, and it's single "No Air" is currently the third-highest-selling single by an "Idol" contestant. She released her second album, "Battlefield," in 2009 and became the only contestant to have her first five singles reach the top 20 on the Billboard 200 chart. She's won one Grammy, an NAACP Image Award, a BET Award, an American Music Award, a People's Choice Award and two Teen Choice Awards. She took a five-year break from music to pursue a career in acting and Broadway, but she released her third studio album "Right Here, Right Now," in August 2015.

"It's definitely bittersweet, the show really gave me my start," Sparks said on The Meredith Vieira Show back in May. "I wouldn't be doing what I'm doing now if it hadn't been for that show. For me, I love that it gave every day people a chance to live out their dreams. I am all for that so I'm sad to see that go because it's the end of an era. What are we going to watch now?"

Jennifer Hudson

Hudson did not win "Idol" but is still such a huge name and successful artist even though she came in 7th place during the third season. She is not only a singer, but an actress as well and made her film debut in the hit 2006 movie "Dreamgirls," which she won an Academy Award for Best Supporting Actress, a Golden Globe, a BAFTA Award and a Screen Actors Guild Award. She also won a Grammy for her debut album "Jennifer Hudson," which she released in 2008. She has since released one more album, but she has mainly focused on her acting career. She also became the spokesperson for Weight Watchers in 2010.

"I'm kind of sad to see it go because it's been a part of our homes," she told E! News last month. "So it's going to be sad to see it go but I hope to be a part of the farewell."

Adam Lambert

Lambery still rose to fame despite being the runner up of season eight. Since 2009, he has released three studio albums and one Grammy nomination. He became the first openly gay artist to top the album charts with his second album "Trespassing," which premiered at number one on the Billboard 200. He has also collaborated with rock band Queen as the lead vocalist since 2011, and they have been on a successful world-wide tour since 2014.

While he is grateful for the success the show brought him, he won't really miss the show. "I think it's about time," he told HuffPost Live in June, according to Us Weekly.

Kellie Pickler

Pickler finished in sixth place during the fifth season but is still a huge name in country music. She has released four albums since her time on the show and even competed on, and won, "Dancing With the Stars" with her partner Derek Hough in 2013.

"Everything that starts comes to an end at some point," she told People in May. "It changed my life and so many others, and I was so blessed to be a part of the show."

Fantasia Barrino

She won the third season in 2004 and released her debut single "I Believe," which debuted at number one shortly after. Her debut album "Free Yourself" received three Grammy Nominations two years later. Her second album "Fantasia" topped the Billboard Hot R&B/Hip-Hop Songs chart for eight weeks and also received three Grammy nominations. She then moved on to Broadway and starred as the lead role of Celie in the musical "The Color Purple." Fantasia later won a Grammy for her third studio album in 2010 before going back to Broadway in 2013 and performing in the musical "After Midnight."

Clay Aiken

Aiken placed second during the second season in 2003 and was also offered a record contract by RCA Records. He has since released five albums under the label. He then moved to Decca Records where he released two more albums. Since then, he's written a New York Times best-selling book "Learning to Sing: hearing the Music in Your Life," accepted a UNICEF ambassadorship, made his Broadway debut and ran for Congress in North Carolina's 2nd congressional district in 2014.

He helped the judges during the auditions in Philadelphia for the final season. "I didn't know how big of a deal it would be for me," he told Billboard. "I didn't know 13 years ago on the streets of Atlanta how life changing it would be."

Chris Daughtry

He came in fourth place during the fifth season but was still given a record deal by RCA Records where he went on to form a band called Daughtry. Their self-titled debut album became the fastest selling debut rock album in history and sold more than 1 million copies in just five weeks of release. This made him the third most successful "Idol" contestant in terms of record sales, behind Clarkson and Underwood.

"It was the best thing that ever happened, as far as my career is concerned," he told People in June. "Otherwise, people wouldn't have a clue who I was."

Scott McCreery

He won the 10th season in 2011, and his debut album "Clear as Day" was certified platinum that same year. He has since released two more albums, and on his third album, his song "See You Tonight" became his first to reach the top 10 on Billboard's Country charts.

"It's bittersweet for me," he told Billboard on the show ending. "It's cool to have its farewell season and I'll be a part of it in different ways, especially the finale. That show has brought a lot to pop culture. It was a pretty dominant factor in pop culture for the last 15 years. It produced artists like myself, Carrie Underwood, Kelly Clarkson, Kellie Pickler. In country music alone, 'Idol' really helped out in that aspect and produced some stars. I'm just glad to be a part of what the show was about for the past 15 years. It'll be sad to see it go. It definitely was a huge part of my life. It was a big platform for me, and I'm really grateful and thankful for it. It will be missed."

Season 15 premieres on FOX on Jan. 6 at 8/7c.