I'm a huge fan of Science Fiction films so I thought I'd share a list of my favorites with the hope that someone finds something new, and include a fun fact on them. These are generally sorted by release date.

Part I: The Before Times; the 60's & 70's
Part II: The Awesome 80's
Part III: The 90's; Bigger & Badder
Part IV: Into the 21st Century

2001: A Space Odyssey (1968)

Director: Stanley Kubrick (A Clockwork Orange, Dr. Strangelove, Full Metal Jacket)
Starring: Keir Dullea, Gary Lockwood
Summary: Based on the novella 'The Sentinel' by Arthur C. Clarke. At the dawn of man, a featureless black monolith appears to a group of ape-men. Millions of years later men uncover another monolith, which sends a signal into space
Fun Fact: Stanley Kubrick made this film as an attempt the make "the proverbial good science fiction movie".

The Andromeda Strain (1971)

Director: Robert Wise (West Side Story, Sound of Music, Star Trek: The Motion Picture)
Starring: Arthur Hill, James Olsen, Kate Reid, David Wayne
Summary: A group of scientists investigate a deadly contaigon after a government probe crashes in a remote town.
Fun Fact: Effects, footage, and props from this film were reused in The Six Million Dollar Man, The Bionic Woman, Knight Rider, and Airwolf.

Westworld (1973)

Director: Michael Crichton (The Great Train Robbery)
Starring: Yul Brynner, Richard Benjamin, James Brolin
Summary: Two guests visit a theme-park where androids make any fantasy possible.
Fun Fact: First feature film for Michael Crichton, most known for authoring The Andromeda Strain, Jurassic Park, Sphere, and Rising Sun.

Close Encounters of the Third Kind (1977)

Director: Stephen Spielberg (Schindler's List, E.T., Raiders of the Lost Ark)
Starring: Richard Dreyfuss, Teri Garr
Summary: After an experience he can't explain, Roy Neary struggles to understand what has happened to him and others like him.
Fun Fact: The opening scene was acted by real air traffic controllers and the synthesizer (keyboard) technician was the actual engineer sent by the manufacturer.

Star Wars (1977)

Director: George Lucas (THX 1138, American Graffiti)
Starring: Mark Hamill, Harrison Ford, Carrie Fisher
Summary: Luke Skywalker learns the Force and joins the Rebellion against the Galactic Empire.
Fun Fact: Han shot. Period. Greedo just died.

Alien (1979)

Director: Ridley Scott (Black Hawk Down, Gladiator, Thelma & Louise)
Starring: Sigourney Weaver, Tom Skerrit
Summary: The crew of the spaceship Nostromo find more than they bargained for while investigating the distress signal from another derelict ship.
Fun Fact: Harrison Ford turned down the role of ship's captain.

Part II: Coming Soon