Deathskull and I got on the topic of good sci-fi movies, so I thought I'd throw together a list of some of my favorites:
2001: A Space Odyssey - A beautiful film. The ending is about death (it's complicated).
Akira - Scientists trigger the amazing powers inside of a young man, turning him into a monster.
Alien and Aliens - Ridley Scott and James Cameron's films define an era in creature horror.
The Andromeda Strain - A race to contain a killer virus. Great production on this.
The Black Hole - One of Disney's more successful attempts at sci-fi. This movie is pure fun, and the Maximilian robot will give you nightmares.
Blade Runner - A cop dives into the seedy underworld of a neon metropolis to solve a murder. Oh yeah, and half of the people are replicants.
Brazil - Oppressive government got you down? Call up your friendly local HVAC Specialist/Freedom fighter.
Dune - A boy becomes a man, becomes a king, becomes a demigod- all on a god-forsaken desert planet, and he kicks some serious ass.
Event Horizon - There's trouble brewing on board a space ship. Don't mess with black holes!
The Fifth Element - It's easy to love Milla Jovovich and everything else about this movie.
Ghost in the Shell - This anime is so good it's scary good. A robotic woman kicks ass, but is she more than just a sexy killing machine?
Mad Max - Set in post-apocalyptic Australia, a renegade cop seeks revenge for the death of his family.
Moon - The lone inhabitant of a lunar facility has a guest. Who is he?
Minority Report - A cop uses 'Procogs' with psychic abilities to spot crimes before they happen. But what happens when they point the finger at him?
Logan's Run - A man is determined to escape from his underground city, avoiding certain death after being selected for 'Carousel'.
Outland - Sean Connery does some hard time in a prison in space.
Paprika - Exciting and colorful story of a young woman who helps people in their dreams.
Pitch Black - Survivors of a crash landing on a remote planet are about to find out why the rest of the planet is dead.
Robocop - After being almost shot to death, a Detroit police officer is reassembled into the ultimate cyborg, but does he still have his humanity?
A Scanner Darkly - Drugs are bad, mmmkay.
Serenity -Joss Whedon blah blah blah + Summer Glau blah blah blah = AWESOME FLICK.
Silent Running - Going against the wishes of his superiors, a man sets out to save what he loves most: life, and destroys his own in the process.
Starship Troopers - A war between man and 'the bugs'. The action sequences inspired many video games.
THX-1138 - Tired of being controlled, THX-1138 leaves the city, but not without opposition from some robot biker cops.
Total Recall - A man wins a virtual vacation package to be implanted in his memories, but then finds that he's stuck inside of that world.
I feel that all of these are incredible movies, and that you can't go wrong with any of them. Feel free to ask me questions about any of these, and pick out some that you haven't seen and watch them!
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Update - FrameShifter has some recommendations too:
DennÅ Coil - The latest technological marvel are glasses that enable one to see an alternate virtual reality. Some school kids get a bit too deep into the tech.
Planetes - Humans are starting to explore space, this story is told about a team of debris collectors near Earth.
WALL-E - Earth is an abandoned trash heap with only compactor robots like wall-e to clean it up. His 'life' changes when a stranger arrives.