Conor McGregor

Conor McGregor didn't just change his own career trajectory — he changed the economics of an entire sport. The Dubliner talked his way into a featherweight title shot, knocked out José Aldo in 13 seconds, then became the first fighter in UFC history to hold two belts simultaneously by stopping Eddie Alvarez at lightweight in 2016.

The weapon was always the left hand — a counter delivered with sniper timing off a karate-influenced stance — and the fight IQ to walk opponents onto it. 19 of his 22 wins are knockouts, and prime McGregor's precision remains some of the cleanest striking footage the sport has produced.

The second act was louder than it was successful: the boxing detour against Floyd Mayweather, the bitter Khabib Nurmagomedov rivalry, the trilogy with Dustin Poirier that ended with a broken leg in 2021. He hasn't won inside the octagon since 2020, and the comeback has been permanently 'next year' for half a decade.

Yet the gravitational pull never faded. Ranked or not, active or not, McGregor remains the biggest name in the sport's history — and the one fight every champion would still take.