What Are The Best / Your Favorite Sci-Fi Movies?

[White Borders]

Originally Posted by Butch7999

There's a thin blurry line between actual science fiction and what we'd call "space opera" or "space fantasy,"
which certainly has its charms (e.g., Flash Gordon, Star Wars), and a slightly broader but no less blurry line
between sci-fi and monster-horror. Anyone up for that discussion?

To me Science Fiction is a very broad category encompassing many genres/elements including:

Time Travel (The Time Machine)
Futuristic Settings/Technology/Weapons (Logan's Run)
Space Travel (Mission to Mars)
Space Opera (The Last Starfighter)
Super Heroes (Batman v Superman)
Alien Invasion (Pacific Rim)
Creature Features (Tremors)
Post Apocalyptic (A Boy and His Dog)
Psychological/Thriller-Suspense/Horror Sci-Fi (The Butterfly Effect/Escape Room/Resident Evil)

But I do see Sci-Fi as being distinctly separate from:

Fantasy (Lord of the Rings, Alice in Wonderland, Maleficent)
Action/Adventure (Indiana Jones, Tomb Raider, Jumanji)
Pure Horror (A Nightmare on Elm Street, Rosemary's Baby, The Shining)