Marion Jones
Jones became a U.S. icon when she won three Olympic gold medals in 2000. However, she fell foul of the BALCO investigation and proved that her legacy was too good to be true (via MSN).

The Olympic committee stripped her of her five medals and she received a six-month jail sentence. That’s because she lied to investigators and misled the court. It was a shambles but she brought the pain upon herself. She destroyed her reputation because she was too afraid to lose.