Joshua R. Floum, 51

After several years of preparation, Floum led the San Francisco-based electronic payments network through its successful transformation from a bank association joint venture into an independent global company. Then in March 2008, he took the company public with the largest initial public offering in U.S. history, worth $19.7 billion. He also developed a plan through which the U.S. banking industry shares responsibility with Visa for large competition lawsuits in exchange for company equity. That strategy led to recent settlements with competitors American Express and Discover, for which Visa paid nothing. Meanwhile, he's crafting his team of 41 lawyers into a global legal department.