18. Satya Nadella
When Satya Nadella took the top Microsoft job six months ago, he said the Redmond, Wash., giant must rediscover its soul. Microsoft is indeed a more imaginative, creative and focused company with Nadella at the helm. His mobile-first, cloud-first productivity and platform offensive already is paying off with a 147 percent increase in commercial cloud revenue in the company's fourth quarter ended June 30.