I'm so, so late with this, but I watched 2001: A Space Odyssey last night. Really enjoyed it even though I wasn't originally in the mood for a slow/weird film! The effects and camera work are really good, can't figure out how some of it was done still so I'm gonna have to have a rewatch some time. I have no idea what it was really about though.
Alien super-power seeds the universe with Monoliths which identify biological traits that can lead to intelligence and enhance them, guiding animal life toward spacefaring civilisation.
The ones the apes at the start discovered prompted their advancement into humans, the one on the moon was a development marker that showed a species had developed spaceflight and the ability to find it when buried and the one near saturn/jupiter (depending whether its the book or film) was to accelerate humans to some next step in assisted evolution.
HAL went nuts because of some cliched 'does not compute' contradiction between being programmed to be honest, but follow instructions, but then being ordered to withold all the information behind the Discovery mission from the crew ('he' was the only 'crew member' that knew everything about it with the discovery on the moon and the signal (noise the monolith made) to saturn/jupiter). The only way out that was allowed to him with all that was to kill the crew, apparently.
Needless to say, the book/s are better, despite the film being as good as it is. If you know whats going on its all there to figure out, but theres more depth and discussion in the books.