I have so many. Star Wars and Empire are favorites, but if I never see either again I’d be okay, since I’ve seen them so much when I was a kid (I’d certainly buy the unaltered originals if they were released).

These are in no particular order, and I’m not gonna bother with adding dates since they’re from all over the years of cinema:

Barbarella - my favorite movie of all time, but I consider:
Blade Runner - to be the best sci-fi film, that is until I watched:
Ex Machina - I just fell in love with it.

Silent Running
Death Race 2000
A Boy and His Dog
Star Crash
Zardoz
The Dark Crystal
The Neverending Story
Destination Moon
Metropolis
The Brood
The Fly
The Thing
Alien
Forbidden Planet
The Holy Mountain
El Topo
Santa Sangre
The Ice Pirates
Brainstorm (Highly underrated. Check it out.)
Super
The Secret of NIMH
Sleeper
Triangle
Return to Oz
The Incredible Shrinking Man
Hellraiser
Pontypool
2001
On the Silver Globe
Galaxy of Terror
Forbidden World
The Prestige
Children of Men
Poltergeist
Battle Royal
Kotoko
Gemini
The Fall
Moon
Robinson Crusoe on Mars
The Black Hole
Time After Time
Primer
Ikarie XB-1
Cosmic Journey
Journey to the Far Side of the Sun
Planet of the Vampires
Gattaca

And there are a lot more, but I don’t have access to my movie collection, so I can’t check. Obviously I like a lot of the standards like Terminator, Inception, Gremlins, The Road Warrior, Brazil etc, but I wouldn’t consider them my favorites. If I listed my honorable mentions (Starman, anyone?) I’d be here all day.