Larry Ellison
Net Worth: $25 billion
Dropped out of University of Illinois
Chicago-bred tech tycoon studied physics at U. of Chicago; didn’t graduate. Started Oracle in 1977. Took public in 1986, one day before Microsoft. Companies have been fiercely competitive since. Side bet: invested $125 million in Web software outfit NetSuite. Still yearning to win yachting’s most prestigious trophy, the America’s Cup. Lost last year to Luna Rossi. Also owns 453-foot Rising Sun; building a smaller leisure boat because megayacht is hard to park.

Roman Abramovich
Net Worth: $23.5 billion
Dropped out of college
Orphaned as a child, Abramovich dropped out of college, then made a fortune in a series of controversial oil export deals in early 1990s. His fortune took off in 1995 when he teamed up with Boris Berezovsky (now also a billionaire) to take over oil giant Sibneft at a fraction of its market value. He spent some of his cash buying U.K. soccer club Chelsea. He recently finalized divorce from the mother of his five children, Irina, but largely stays out of public eye, except for occasional spottings with rumored girlfriend Daria Zhukova.

Amancio Ortega
Net Worth: $20.2 billion
Left school at 14
With help from then-wife Rosalia Mera, got start making dressing gowns and lingerie in their living room 45 years ago. Business became one of world’s most successful apparel manufacturers, $14.8 bil (2007 sales) Inditex. Group now has 3,902 stores in 70 countries. Ortega is chairman. Owns a horse-jumping circuit and part of a soccer league. Shuns neckties. Ortega may be looking to his succession. Daughter Marta is now working at Inditex; reports are she is being groomed to eventually take his place.

Francois Pinault And Family
Net Worth: $16.9 billion
Dropped out of high school
Majority shareholder of luxury goods group PPR (formerly Pinault-Printemps-Redoute), whose brands include Gucci, Balenciaga and Stella McCartney. Also owns more affordable catalog brands Lerner and Chadwick’s. Pinault, who also owns auction house Christie’s, scrapped plans for a 352,000-square-foot museum in the former Renault factory in western Paris because of supposed red tape. His personal art collection is now showcased in Venice in the Palazzo Grassi. Was awarded the French Legion d’honneur last year.