5. Adam Lambert
Runner-up; Season 8
Number of albums sold: 2,115,000
Net worth: $12 million
Adam Lambert’s unique and unusual renditions of songs during the run of the show made him insanely popular. He always received great praise from the judges and rose to fame pretty quickly. Such was his success that he appeared as a mentor in season 13 of American Idol and as a guest judge during the auditions of season 14. He has released three studio albums in his music career, which have sold more than 2 million copies combined.
