Most all around skilled fighter EVER?
I've got to go with BJ Penn in his prime, at 155.
You could easily argue he had the best boxing, takedown defense, and BJJ in the game, all at the same time. He also has very under-rated takedowns. His only weakness was kicks, he never was a kicker. But he didn't need to be.
Bas (though he had by far the weakest competition, he still had a very broad skillset)
Events Attended: UFN 1, UFC 64, UFC 66, Pride 33, UFC 71, UFC 74, WEC 39, UFN 19, UFC 103, SF: Fedor vs. Rodgers, SF: Hendo vs. Shields, UFC 129, SF: Alistair vs Werdum, UFC 136, UFC 148, UFC 178