4. Clay Aiken, Season 2
How Far Did He Go: Runner-up
Most Memorable Performance: Simon & Garfunkel's "Bridge Over Troubled Water"
Biggest Hit: While his Idol single, "This is the Night," went Number One after the finale, his first non-Idol wins were on 2003's Measure of a Man. The album went double platinum, debuted at Number One on Billboard and was the highest solo artist debut since Snoop Dogg's Doggystyle. It included "Invisible" and "The Way."
Career: Aiken almost auditioned for The Amazing Race instead of American Idol, but at the urging of a friend, he decided to go the singing route. He was cut in the Top 32 of season 2, let back in as a wild card, and then brought to the Top 12 as an audience favorite. He made it all the way to the final, coming in second to Ruben Studdard by a divide of only 134,000 votes out of 24 million cast, thanks to his Claymates, one of the earlier forms of fan armies that helped spur along his career. Post-show, he had Billboard hits in 2003, eventually releasing seven albums total throughout his career. In 2008, Aiken was certainly busy: He made his Broadway debut in Spamalot in January, welcomed his son in August and came out as gay that September. In 2012, he starred on The Celebrity Apprentice with now-presidential candidate Donald Trump, again placing second, this time losing to Arsenio Hall. He even went political, running as the Democratic nominee for North Carolina's Second Congressional District in 2014, but lost to the Republican incumbent Renee Ellmers in the midterm election.