Floyd Mayweather is a man so rich that his nickname is 'money', and if you're going to choose a name like that for yourself, you have to live up to it. We don't think anyone can accuse Mayweather of missing an opportunity to line his own pockets. Whilst the boxing world laughed at and derided his boxing vs UFC clash with Conor McGregor, Mayweather was laughing back at them and watching his bank account swell by $300m.
It took serious talent for Mayweather to get where he is - he was arguably, pound for pound, the best boxer in the world for a long time, beating Manny Pacquiao to end any real debate about that. He now claims to be retired for the final time, meaning he leaves the sport with a career record of 50-0, undefeated. Outside the ring, he's competed in a wrestling match for WWE at 'WrestleMania', and was also a contestant on 'Dancing with the Stars'.