55. Diane Nelson

As head of Warner Bros.' direct-to-DVD division and manager of the massive "Harry Potter" brand, Nelson's attentions are naturally divided: In one job, she makes sure small films like this year's "Lost Boys: The Tribe" and "Another Cinderella Story" get seen; in the other, she oversees a $5 billion franchise (including a theme park set to open in Orlando in 2010).

"It's probably as difficult, if not somewhat more difficult, to create a $4.5 million movie rather than an $85 million one," says Nelson, who also started the brand management group at Warners. "You have to be very careful." There's more magic for her in 2009, with the latest wizard installment "Harry Potter and the Half-Blood Prince" due in July, as well as smaller franchise films like "Scooby Doo: In the Beginning." But it's her third managing position that keeps her really hopping -- as CEO of two young boys and a new puppy named Toby.