Conor McGregor

McGregor's press conference at UFC 194 — "I'd like to take this chance to apologize... to absolutely nobody" — is the single greatest promotional moment in UFC history. The problem is that his mouth peaked around 2016 and his fighting peaked around the same time. Since beating Eddie Alvarez for the double champ status, he's gone 1-3 in MMA and 0-1 in boxing. He's still the biggest PPV draw in combat sports, selling 6.5 million buys for Mayweather alone. The brand outlived the performance.