As voted for by members of IMDB:
1 Star Wars (1977) 8.7/10 (84651 votes)
2 Dr. Strangelove or: How I Learned to Stop Worrying and Love the Bomb (1964) 8.7/10 (35253 votes)
3 Star Wars: Episode V - The Empire Strikes Back (1980) 8.6/10 (65448 votes)
4 Matrix, The (1999) 8.4/10 (76513 votes)
5 2001: A Space Odyssey (1968) 8.3/10 (39891 votes)
6 Alien (1979) 8.2/10 (35659 votes)
7 Metropolis (1927) 8.2/10 (5897 votes)
8 Clockwork Orange, A (1971) 8.2/10 (36279 votes)
9 Blade Runner (1982) 8.1/10 (46741 votes)
10 Donnie Darko (2001) 8.1/10 (7254 votes)
11 Aliens (1986) 8.1/10 (38564 votes)
12 Minority Report (2002) 8.1/10 (15354 votes)
13 Star Wars: Episode VI - Return of the Jedi (1983) 8.0/10 (49958 votes)
14 Day the Earth Stood Still, The (1951) 7.9/10 (5629 votes)
15 Terminator 2: Judgment Day (1991) 7.9/10 (43347 votes)
16 Brazil (1985) 7.9/10 (18757 votes)
17 Iron Giant, The (1999) 7.9/10 (7774 votes)
18 Back to the Future (1985) 7.9/10 (38661 votes)
19 Terminator, The (1984) 7.8/10 (32770 votes)
20 Twelve Monkeys (1995) 7.8/10 (36865 votes)
21 Invasion of the Body Snatchers (1956) 7.8/10 (2789 votes)
22 Abre los ojos (1997) 7.8/10 (3650 votes)
23 Planet of the Apes (1968) 7.8/10 (11002 votes)
24 Spider-Man (2002) 7.8/10 (25608 votes)
25 Close Encounters of the Third Kind (1977) 7.7/10 (16046 votes)
26 E.T. the Extra-Terrestrial (1982) 7.7/10 (25394 votes)
27 Fail-Safe (1964) 7.7/10 (1934 votes)
28 Lost Horizon (1937) 7.7/10 (1116 votes)
29 Truman Show, The (1998) 7.7/10 (39024 votes)
30 Delicatessen (1991) 7.7/10 (6873 votes)
31 Signs (2002) 7.7/10 (13435 votes)
32 Invisible Man, The (1933) 7.7/10 (1139 votes)
33 Cité des enfants perdus, La (1995) 7.6/10 (6490 votes)
34 Thing, The (1982) 7.6/10 (8565 votes)
35 Lilo & Stitch (2002) 7.6/10 (3291 votes)
36 Forbidden Planet (1956) 7.5/10 (4336 votes)
37 Star Wars: Episode II - Attack of the Clones (2002) 7.5/10 (31439 votes)
38 Seconds (1966) 7.5/10 (874 votes)
39 Thing From Another World, The (1951) 7.5/10 (1407 votes)
40 Akira (1988) 7.5/10 (7941 votes)
41 Night of the Living Dead (1968) 7.5/10 (5620 votes)
42 Incredible Shrinking Man, The (1957) 7.4/10 (755 votes)
43 Dawn of the Dead (1978) 7.4/10 (5506 votes)
44 Star Trek: The Wrath of Khan (1982) 7.4/10 (10344 votes)
45 Dark City (1998) 7.4/10 (13484 votes)
46 Mad Max 2: The Road Warrior (1981) 7.4/10 (7158 votes)
47 Pi (1998) 7.4/10 (9853 votes)
48 Frequency (2000) 7.4/10 (9067 votes)
49 Ghost Busters (1984) 7.4/10 (17593 votes)
50 Gattaca (1997) 7.4/10 (14130 votes)
**********************************************************
Bear in mind that it is likely that more recent movies will likely have an advantage as members see new releases. I think it is quite a good overview of science fiction films, I can't think of any that should be in here, but that haven't rated.
I have seen 42 - not bad going, several of the ones I have never seen I haven't actually heard of. How many have you seen?
Abre Los Ojos
Lost Horizon
La Cité des enfants perdus
The Invisible Man
Lilo & Stitch
Seconds
Delicatessen - I think I have seen this one actually, but only part of it.
Incredible Shrinking Man
Check this link for info on how the chart is calculated, and for the bottom ten movies (none of which I have seen ):
http://us.imdb.com/Charts/Votes/sci-fi
1 Star Wars (1977) 8.7/10 (84651 votes)
2 Dr. Strangelove or: How I Learned to Stop Worrying and Love the Bomb (1964) 8.7/10 (35253 votes)
3 Star Wars: Episode V - The Empire Strikes Back (1980) 8.6/10 (65448 votes)
4 Matrix, The (1999) 8.4/10 (76513 votes)
5 2001: A Space Odyssey (1968) 8.3/10 (39891 votes)
6 Alien (1979) 8.2/10 (35659 votes)
7 Metropolis (1927) 8.2/10 (5897 votes)
8 Clockwork Orange, A (1971) 8.2/10 (36279 votes)
9 Blade Runner (1982) 8.1/10 (46741 votes)
10 Donnie Darko (2001) 8.1/10 (7254 votes)
11 Aliens (1986) 8.1/10 (38564 votes)
12 Minority Report (2002) 8.1/10 (15354 votes)
13 Star Wars: Episode VI - Return of the Jedi (1983) 8.0/10 (49958 votes)
14 Day the Earth Stood Still, The (1951) 7.9/10 (5629 votes)
15 Terminator 2: Judgment Day (1991) 7.9/10 (43347 votes)
16 Brazil (1985) 7.9/10 (18757 votes)
17 Iron Giant, The (1999) 7.9/10 (7774 votes)
18 Back to the Future (1985) 7.9/10 (38661 votes)
19 Terminator, The (1984) 7.8/10 (32770 votes)
20 Twelve Monkeys (1995) 7.8/10 (36865 votes)
21 Invasion of the Body Snatchers (1956) 7.8/10 (2789 votes)
22 Abre los ojos (1997) 7.8/10 (3650 votes)
23 Planet of the Apes (1968) 7.8/10 (11002 votes)
24 Spider-Man (2002) 7.8/10 (25608 votes)
25 Close Encounters of the Third Kind (1977) 7.7/10 (16046 votes)
26 E.T. the Extra-Terrestrial (1982) 7.7/10 (25394 votes)
27 Fail-Safe (1964) 7.7/10 (1934 votes)
28 Lost Horizon (1937) 7.7/10 (1116 votes)
29 Truman Show, The (1998) 7.7/10 (39024 votes)
30 Delicatessen (1991) 7.7/10 (6873 votes)
31 Signs (2002) 7.7/10 (13435 votes)
32 Invisible Man, The (1933) 7.7/10 (1139 votes)
33 Cité des enfants perdus, La (1995) 7.6/10 (6490 votes)
34 Thing, The (1982) 7.6/10 (8565 votes)
35 Lilo & Stitch (2002) 7.6/10 (3291 votes)
36 Forbidden Planet (1956) 7.5/10 (4336 votes)
37 Star Wars: Episode II - Attack of the Clones (2002) 7.5/10 (31439 votes)
38 Seconds (1966) 7.5/10 (874 votes)
39 Thing From Another World, The (1951) 7.5/10 (1407 votes)
40 Akira (1988) 7.5/10 (7941 votes)
41 Night of the Living Dead (1968) 7.5/10 (5620 votes)
42 Incredible Shrinking Man, The (1957) 7.4/10 (755 votes)
43 Dawn of the Dead (1978) 7.4/10 (5506 votes)
44 Star Trek: The Wrath of Khan (1982) 7.4/10 (10344 votes)
45 Dark City (1998) 7.4/10 (13484 votes)
46 Mad Max 2: The Road Warrior (1981) 7.4/10 (7158 votes)
47 Pi (1998) 7.4/10 (9853 votes)
48 Frequency (2000) 7.4/10 (9067 votes)
49 Ghost Busters (1984) 7.4/10 (17593 votes)
50 Gattaca (1997) 7.4/10 (14130 votes)
**********************************************************
Bear in mind that it is likely that more recent movies will likely have an advantage as members see new releases. I think it is quite a good overview of science fiction films, I can't think of any that should be in here, but that haven't rated.
I have seen 42 - not bad going, several of the ones I have never seen I haven't actually heard of. How many have you seen?
Abre Los Ojos
Lost Horizon
La Cité des enfants perdus
The Invisible Man
Lilo & Stitch
Seconds
Delicatessen - I think I have seen this one actually, but only part of it.
Incredible Shrinking Man
Check this link for info on how the chart is calculated, and for the bottom ten movies (none of which I have seen ):
http://us.imdb.com/Charts/Votes/sci-fi