The 2010 TIME 100

In the nine seasons he's spent as an acerbic, V-neck-T-shirt-wearing judge on American Idol, Simon Cowell, 50, has made an indelible impression on global pop culture. Idol has lured viewing audiences in excess of 37 million and spawned imitators in 43 countries. With Idol, America's Got Talent and the coming X-Factor, Simon has helped make reality shows the most popular on television, a medium for audiences to connect with authentic human drama. But watching Simon stay true to himself and never falter has been one of the most inspirational messages of Idol's phenomenal run. Contestants may fear him, but those who know him know he is humble, generous and compassionate. His shows offer positive themes and, for their participants, life-changing opportunities. At the end of the day, Simon Cowell makes dreams come true. My dream is to follow in his footsteps — wearing a tight-fitting V-neck T-shirt.

Cannon is the host of the NBC TV show America's Got Talent

TIME 100 Social-Networking Index: 171,726