Jon Jones
Many people believe that Jones is the greatest MMA fighter of all time. Incredibly, he remains in the conversation because he’s undermined his career with high amounts of partying. Yes, he’s a two-division UFC champion but he will never be the mainstream star that he could have been. Cocaine and alcohol damaged Jones’s commercial marketability.

He infamously crashed his vehicle into a pregnant woman’s car before fleeing the scene. Then there was also the time he drank a bottle of mezcal, went for a drive, and fired his pistol into the air. The Albuquerque police rolled their eyes when they arrived at the scene because they knew Jones’s reputation (via New York Post).