Ingvar Kamprad

IKEA founder Ingvar Kamprad is the fourth-richest man in the world, trailing only Bill Gates, U.S. investor Warren Buffett and Mexican industrialist Carlos Slim Helu. Kamprad, whose fortune is estimated at roughly $28 billion, turns 80 in March and is considered eccentric by many critics. Why? Simply because he's frugal. Kamprad drives a 15-year-old Volvo, flies economy coach and tells his IKEA employees to write on both sides of the paper. And he doesn't apologize for any of it.