Who is it that finally kills TheDuke? The formerly-milquetoast President of the United States.
Snake's victory against the Giant Mook in the ring. The guy is twice Snake's size, and Snake has been limping since he was shot in the leg with an arrow. He finally sees his chance and hits his opponent in the stomach with his spiked club, and then again in the back of the head! And the previously hostile crowd goes wild! "SNAKE, SNAKE, SNAKE, SNAKE!!!"
"Snake Plissken? I heard of you. I heard you were dead."
The president announces that he has something to share in the spirit of peace. Cue the tape playing some old time jazz number, while the camera cuts to Snake tearing up the tape with the data on nuclear fusion.
Meta example, but according to a recent interview: While they were filming, Kurt Russell decided to take a stroll through an alleyway in full Snake attire, guns and all. He met 4 guys who he described as tougher than him. They were so intimidated that they left him alone. You heard that folks, Snake was a Badass before he hit the big screen. Though he remarked that by now almost everyone has seen the movie and wasn't sure that could work again.