Star Trek II The Wrath of Khan Rise of the Planet of the Apes (the other two as well. Excellent trilogy) The Terminator Interstellar Alien Some additional "bad" Sci Fi I like... The Black Hole The Core (considered terrible for it's bad science. I don't care, I like it anyway) Krull Flash Gordon (1980) Ok I am big Star Wars fan and those movies have been a great source of enjoyment in my life since I saw the original at age 6 or 7. But I think they fall into the mythology fantasy genre and I think even George Lucas would agree. Without the smart editing, innovative sound effects and brilliant score by John Williams Star Wars might have been a cult classic film instead.
Here's what I'm going with today: Brazil (1985) Being John Malkovich (1999) Vanilla Sky (2001) Primer (2004) Time Lapse (2015)
have the DVD: Blade Runner Planet Of The Apes (original) Alien Metropolis THX 1138 don't have the DVD (aka next five): 2001 Silent Running Solaris (original) Moon Forbidden Planet pure nostaliga (saw on release) list: Star Wars Logan's Run Damnation Alley The Empire Strikes Back Close Encounters exotic foreign list: Ikarie XB-1 Warning From Space Planeta Bur Moon Zero Two (UK '60s is exotic for me) Gamera vs. Viras
5. The Thing (1982) 4. Star Trek: The Motion Picture 3. Alien 2. Star Wars: The Empire Strikes Back 1. Blade Runner
2001: A Space Odyssey (1968) Blade Runner (1982) They Live (1988) A.I. Artificial Intelligence (2001) District 9 (2009)
Forbidden Planet The Day the Earth Stood Still 2001 The Time Machine (original) First Men in the Moon
Tough question as I'd place many S-F movies as horror (Alien) or action (Aliens). The presence of a space-ship does not automatically make it science-fiction, IMHO. Metropolis (2010 restored version) Ghost in the Shell (animated) Blade Runner Contact Dune (fingers crossed that the coming one replaces the Lynch version!)
Technically, it's historical fiction as it takes place a long time ago in a galaxy far away. So his-fi.
Invasion of the Body Snatchers Blade Runner They Live Forbidden Planet The Thing from Another World But that's subject to change. 5 is way too hard.
The Thing From Another World 2001 A Space Odyssey Forbidden Planet Earth Vs the Flying Saucers Quatermass and the Pit ...for now.
My immutable five: The Invisible Man 1933 Invasion of the Body Snatchers 1956 Village of the Damned 1960 Sleeper 1973 Fifth Element 1997 Gravity would have made my list but I don't know that it's science fiction. First Men in the Moon (elaterium, above) is an often ignored gem. I eliminated a number of more recent films because they are remakes or because, for me, they are horror movies with science fiction elements.
Off the top of my head: Fantastic Voyage (1966) The Langoliers (miniseries) (1995) Star Trek First Contact (1996) Terminator 3: Rise of the Machines (2003) Serenity (2005)
War Of The Worlds (1953) The Day The Earth Stood Still (1951) Aliens (1986) Blade Runner (1982) Total Recall (1990)