#1 Bruce Lee
Bruce Lee is one of those stars who has achieved immortality due to his work in both martial arts and the way he depicted the same in the films that he acted in.
Lee started from a young age, mastering the art of Wing Chun, under Ip Man, or Yip Man. Ip Man used to train students in the martial arts forms and discourage them from fighting in the street, by helping them to compete in organised tournaments instead.
Later during his time in the United States, it was Lee who was the teacher. He taught Jun Fan Gung Fu, which was his own approach and twist to Wing Chun.
He would also appear at the Long Beach Karate Championships where he demonstrated his famous one-inch punch. He notably had a controversial match in private with Wong Jack Man.
This fight would lead to Lee changing his Martial Arts philosophy, adopting a style called Jeet Kune Do, which was based on practicality, flexibility, speed, and efficiency. He called it the style of no style.
Although he had an immensely lucrative career in Mixed Martial Arts, his film career is not far behind. His films, The Way of the Dragon, Fists of Fury, Enter the Dragon, and Game of Death all saw him get a lot of acclaims. He died at the mere age of 32, due to a 'death by misadventure' when a form of tranquillizer was found in his system.
He would still be one of the top men in the UFC in his prime if at all given the opportunity.