As American Idol prepares to exit the airwaves after 15 seasons of innovation and inspiration, PEOPLE takes a look back at the show that shattered records, and reinvented the television competition.Highlights of this musical special edition include: - Exclusive interviews with the contestants and judges - the ones we loved and the ones we loved to hate - A review of the most memorable moments, from William Hung's "She Bangs" to Fantasia's powerhouse performances - A section that reveals what contestants have been up to since their time on Idol - A peek at the biggest successes to come out of the Idol machine, from Adam Lambert to Carrie Underwood