6. ANNA KOURNIKOVA (TENNIS) – $50 MILLION
Anna Kournikova owes her fortune not only to her tennis career, but also to a television career when she was picked to replace Jillian Michaels on The Biggest Loser. She has never won a singles title, but she was very successful playing doubles tennis and ended up ranked at number one for a period of time. Health issues forced her to retire early from tennis, but she continues to build on that success.