It's easily Jon Jones.
- Even as a relatively inexperienced fighter, wiped out veterans Shogun, Rampage, Lyoto, Rashad, Vitor, and Chael. These guys traded wins and losses with each other but Jon was a level above.
- Beat Gus twice, the first one controversially, but the second time decisively after Gus came off wins against future champs Jan and Glover.
- Speaking of Glover, Jon put a 5-round beating on him.
- Beat DC twice, though the 2nd one ruled an NC after Pico-gate. If Jon didn't exist, we would be talking about DC like how we talk about Jon. DC was otherwise unmatched at LHW.
- Derailed a new generation of up-and-comers like OSP, Anthony Smith, Marreta, and Dom Reyes
The only dude at LHW that might have given Jon some trouble because of his size, athleticism, chin, and power, was Rumble. Too bad their match fell through because's of Jon's idiocy. Then again, these two are on the opposite ends of fight IQ. Jon probably still strangles him in the 2nd round.