2. Legion
"Wait, slow down here. Dennis Quaid died in this movie. This article is a fluke. A lie!" Woah - hold on a second! There are times when the rules of physics and atomic matter just don't make sense. And those times are usually in movies when Dennis Quaid is not alive at the end. But in Legion, while DQ does die, he takes his destiny in his own hands. Which seems to be about the only way you can get him to go out, to be honest. Legion is the story of God losing faith in humanity, thus ordering their extinction. But the archangel Michael says "Yo, not cool, God" and decides to help humanity by protecting a prophesied yet-to-be born baby that is said to be the saviour of humanity. Well, the mother bearing the child is currently at a diner ran by Dennis Quaid, Bob, an atheist who despite his beliefs teams up with the other patrons to hold of hordes of possessed people from killing them all. So how does Dennis Quaid die? Well God sends Archangel Gabriel to finish this surprisingly difficult job. Gabriel wounds Bob, although we get the impression he is dead if I am not mistaken. As everyone escapes, Gabriel battles it out with Michael. Then a not-dead Bob says "I don't go out like a punk", igniting the gas main to the diner, taking out the possessed, Gabriel, and himself. God ordered Bob to be killed, and still DQ could not die. That's how impossible it is to kill him. Order the extinction of humanity because you lose faith in them and who says "not today"? An atheist played by Dennis Quaid. Bob sacrifices himself to save others, possibly humanity. So even though Quaid's character dies by the end, I still put this on the list of he is impossible to kill.