Résumé: CEO and chairman, Berkshire Hathaway.
Track record: Your $1,000 invested in Buffett's firm in 1964 was worth $3.6 million 42 years later. "The Sage of Omaha" makes money through Berkshire's stock portfolio and through smart acquisitions. Berkshire sells insurance but also engages in a long list of other businesses, from candy to building supplies.
Biggest impact: As the leading modern proponent of value investing, Buffett focuses on finding great companies at good prices. His folksy annual letters to Berkshire shareholders share investing pointers and also his thoughts on the economy, corporate governance, and managing.
What else: Buffett co-owns a minor-league baseball team, the Omaha Royals.