Who would be your choice for the best fighter in the UFC if you could select one person from any time or style of the last 100 years. A couple people that come to mind who would have been sick with the right training.
Cael Sanderson (perfect 159-0 college wrestling record and recognized as many as the best wrestler ever)
Aleksandr Karelin (3 Olympic gold medal wins and legendary grappler)
Bruce Lee (no explanation needed)
Prime Tyson (there was a time after he KO'd Spinks in 90 seconds that he was as good as you get)
Joe Louis (longest HW title reign in history)
Pacqiuao (striking is obvious, but also has a good understanding of jiu-jitsu)
Rocky Marciano (undefeated in boxing)