1. Conor McGregor
The Irishman is one of the most famous combat sports athletes on the planet. First of all, he won the UFC featherweight title. Then he added the lightweight strap to his collection. This made him the first UFC fighter to hold two titles simultaneously. Suddenly he was the most high-profile MMA fighter ever.
But this wasn’t enough for ‘The Notorious.’ He went after a major payday in Floyd Mayweather. The pair finally fought in 2017 with a lot of attention on the crossover clash. In the end, Mayweather’s boxing prowess was just too much for McGregor. However, he did make nearly $100 million for the fight, so it wasn’t all bad.