American Idol: Season 4 (2005)

The smash reality series showcases wannabe pop stars competing for a record deal by crooning for a panel of judges, including, most entertainingly, the acid-tongued Simon Cowell, who departed the show in 2010 after serving for nine seasons. The judges review a performer's talent (or lack thereof), and at-home viewers then vote for their favorite potential star. The show helped launch the careers of such artists as Kelly Clarkson, Carrie Underwood, Jennifer Hudson and Adam Lambert.