my ratings for the movies on the list i have seen
1. Blade Runner
3. Alien
6. The Matrix
11. The Terminator
14. A Clockwork Orange
16. Star Wars: A New Hope
17. Mad Max 2
19. The Terminator Part 2
22. Empire Strikes Back
25. The Thing
27. Star Trek: Wrath of Khan
28. Total Recall
30. Metropolis
34. Serenity
35. Moon
36. Aliens
39. Predator
40. Star Trek (2009)
42. Jurassic Park
45. Independance Day
46. V For Vendetta
you covered most of my sci-fi favorites... especially the Thing, Alien, Star Wars, Empire, Blade Runner, Terminator and Terminator 2
is They Live considered sci-fi? would have liked to see that one make it. some others i enjoyed not on your list- the Invisible Man (1933), the Time Machine (1960), Forbidden Planet (1956), Close Encounters of the Third Kind (1977), and the Day the Earth Stood Still (1951). but since it's your list,