56. Shonda Rhimes

Drawn away from Harvard Law to the USC film school, within six months of graduation Rhimes had sold a spec script. That kept her in steady writing assignments until she got the call of her dreams: Her medical drama "Grey's Anatomy" was being turned into a series. Five seasons (and one spinoff) later, "Grey's" still pulls in more than 18 million viewers each week.

But despite the success, Rhimes sometimes dreams of a quieter, less hectic life. "I never had a plan B," admits the mother of a 6-year-old. "Now my whole plan B involves living in Vermont and being a librarian, surrounded by books and picking apples. I've seen (1987's) 'Baby Boom' one too many times."