6. David Bowman - 2001: A Space Odyssey (1968)
I just finished reading Arthur C. Clarke's 2001: A Space Odyssey for the first time. The book moved much faster than the movie and the ending is better. That being said, the film version is considered one of the most influential movies of all time. Naturally, a superior movie about a space voyage means we've got one of the greatest astronauts in film history to work with. Our hero, David Bowman is an astronaut headed to Jupiter to check out an ancient alien monolith. Along the way he has to defeat HAL, the super computer that runs the ship (and utters the famous question "What are you doing, Dave?"), and overcome maddening loneliness. Eventually, Bowman makes his way to the moons of Saturn, only to discover that the alien monolith is actually a star gate. The gate whisks him around the universe for a while. When it finally sends him back to Earth, it is in the form of a superior being reborn as a powerful infant.
Why He's Great: David Bowman is the protagonist in the greatest astronaut movie of all time. How could he not be great?