15"Open the pod bay doors, HAL" - 2001: A Space Odyssey
If the words "I'm sorry, Dave. I'm afraid I can't do that" don't haunt you, consider yourself lucky. But for those who have seen the Kubrick classic 2001: A Space Odyssey, HAL, the AI component of the spacecraft headed for Jupiter, is an unforgettable character. Originally a
comfort to the astronauts during periods of solitude on their journey, HAL begins to cause problems, and the pilots discuss the possibility that they might need to turn him off to determine what's wrong.
In the scene in question, HAL reveals that he knows about this plan and refuses the commands of his superior, Dave. While it can be argued that this is included to further bring about the question of man versus machine, it's already been established that HAL is sentient and, frankly, the focus on him gets to be a bit much. Most of the three-minute scene is simply Dave yelling "HAL," and, due to the film's 161-minute running time, probably could have been done without.