My picks:
Forbidden Planet - I cannot believe no one else picked it. My opinion, the best Sci-Fi flick ever made. BRILLIANT adaption from Shakespeare's The Tempest, and beautiful SFX for the day. A wonderful, enigmatic film. 10/10
Prometheus - stop and think about it. Also, look for ALL the clues and hints shown - nothing is explicitly stated in this movie. The sharp eyed watcher will understand this film a LOT more - typical Ridley Scott movie - he does not hand it on a plate to you, he makes you think
Alien - Director's Cut. Fills in a few blanks that were removed in the original. Gripping, suspenseful, dark, and full of H.R Geiger's masterpiece design.
Sunshine - it's quirky, it's different, and it's relatively unheard of, but it is interesting at least.
Alien ³ - DIRECTOR'S CUT - has to be the DC, as the regular box office version sucks rocks. Again, the DC fills in some blanks, changes some premises and ideas; for instance, in the DC, the xenomorph is the product of a cow, whereas the theatre version it came from a dog. I like the filthy, distasteful feel of this movie. NOTE: I am a MAJOR Alien franchise fan, but do NOT like Aliens (typical American bravado and BS fare), nor the French abomination Alien Resurrection. And absolutely NOT the Alien vs Predator series - how dare they!
Carl Sagan's Cosmos may now be dated, but it walked all over De Grasse Tyson's political agenda filled nothingness, that presented essentially - NOTHING! Just when I thought he would start talking about interesting points, that section ends. HUH? And where was really any discussion of the cosmos in it? BIG thumbs down.
Russian Sci-Fi classic Solaris. Psychological, intense, superbly produced. SBS did a translated version, and I think there are other versions available (I watch it in Russian
)
H G Wells The Day the Earth Stood Still - still intense to this day.
War of the Worlds - the original, not the Tom Cruise yakness.
When Worlds Collide - I will always remember the end scene.
Anyway, there ya go, opinion and all