Klatuu barada niktoo! (Or something like that) The Day the Earth Stood Still has always been my most favorite! Next on my list is Forbidden Planet, but then we're in same age group and were raised on those classics!

Blade Runner pure and simple.

I thought I'd add a few films that I don't believe have been mentioned in the discussion: The Road Warrior, Invasion of the Body Snatchers (1950s version) and The Incredible Shrinking Man.

Does The Incredibles count?

No, Star Wars isn't the Greatest of All Time--as far as true cinematic quality goes, it's not so very high. But it can boast of one, and I think a vital, advantage over 2001: A SPACE ODDESSY--Star Wars is fun. It's entertaining, it's rollicking, there's explosions and lightsabers and special effects that were truly impressive at the time. 2001? Slow, ponderous, confusing, and excitement-free. I know which one I'd go see.

That said, I also have an extreme distate for significantly older movies--especially black and white movies--modern filmmakers, whatever their other flaws, have for the most part realized how to tell a story that moves along swiftly and doesn't drag its feet bringing entertainment to the audience. (2001; the Good, the Bad, & the Ugly...I'm looking at you two)

STAR WARS isn't science fiction. It's space fantasy. And on that basis it's the best space fantasy of all time. It's "Lord Of The Rings" in outer space.

FORBIDDEN PLANET, however IS science fiction. And yeah, I also consider it to be the actual, true pilot for STAR TREK.

No love for GATTACA, ya'll?

I feel somewhat obligated to stick up here for Doctor Who, which may not have been a movie until 1996 but damn well ought to get considered if we're to discuss sci-fi greats.

The classification of Star Wars as the "best science fiction film of all time" depends pretty heavily on what you mean by "best." Was it the most creative or innovative? Definitely not. It cribbed so heavily from westerns, samurai movies, and every previous sci-fi epic. Was it the best written? No. Was it the best acted? No. Was it the best directed? No.

On the other hand, was it entertaining? Yes. Did it do a good job creating its alternate universe? Yes, and it continues to flesh that universe out in almost mind-numbing detail. And did it introduce many people to science fiction who otherwise would not have looked its way? Yes. In that respect it's something like what The Matrix has done for the cyberpunk genre in terms of legitimizing it in the eyes of the mainstream audience, which may not seem like much until you consider that it also convinces major purveyors of media that people will buy that sort of thing.

I'll throw in a couple I haven't yet seen mentioned: for my money, one of the best in terms of sheer entertainment has to be Galaxy Quest. Also there's Dark City, Independence Day (wonderful popcorn movie), Starship Troopers, and primer.

Personally I feel there's going to be a real renaissance in science fiction movies soon. Now that special effects and CGI are getting cheaper and cheaper, low-budget scifi flicks are constrained less and less by technology. I predict we'll see writers and directors taking risks in B-movies that the studios don't expect to do more than pay for their keep, and with improved graphics they don't have to limit their stories to what can be portrayed cheaply on screen.

I'm surprised no one has mentioned Metropolis yet. Definitely pioneered the sci-fi genre in film.

Other than that, I know this is a topic about sci-fi films but I thought I'd mention some sci-fi television, the new Battlestar Galactica in particular. It does such a wonderful job of taking basic sci-fi premises and ideas and translating them into a show that is all together human. It's such a great commentary on the human race as a whole while still being a wonderful sci-fi show. It truly a testament to how sci-fi doesn't have to be a niche thing but can appeal to the masses.

Also, I don't know if this is the place to mention anime, but many anime series are great sci-fi series. There's some great storytelling to be had in them.

I haven't seen Forbidden Planet, but I'd say Blade Runner is the best all time sci-fi movie.

I agree. I don't like Star Wars at all.

Wow... I go through your list, and I think, no, that one was bad... I hated that one... that one suck... That's sort of it, anyway.
I liked Star Wars, but it wasn't any sort of best of anything. I guess 2001 was okay, once you cut out the incomprehensible bits. Alien and Aliens were okay, for horror movies, I guess. Hate horror movies so much.
Sorry. Give me a moment to adjust my invective gland. I don't know why I'm talking with so much scorn about something I love. Maybe I'm upset that Hollywood has so rarely come through for me.
I will add Forbidden Planet to my list of movies to see, but I can tell you now that I probably won't like it. Simply because I don't any movies made before, say, 1970. I can understand why older people appreciate older movies, they grew up with them and that's what they expect from movies. But I'm only about to hit 20. Blade Runner was soo sloow and booring. The original Metropolis, a film my father loves, is soo sloow and booring. Because the fact that they are slow compared to modern films make them worse? No. It just makes me hate them. There is a profound difference between being bad and me thinking they are bad. But the upshot is that if I think something is bad, I obviously can't think it's the greatest of all time, now can I?
I thought for awhile, and at first came to the conclusion that I had never seen a truly good sci-fi film. I liked Return of the Jedi and Revenge of the Sith, but they weren't great films. I liked Star Trek: First Contact even more, it might qualify as borderline great.
I liked Titan, A.E., but it is by no means great. I want to see Treasure Planet, but I can tell from the little I know about it that it won't qualify as great.
What are films that I think are truly great? What are my favourite films, leaving out the sci-fi prerequisite? Boondock Saints. Fight Club. V for Vendetta. Maybe the last is borderline scifi. Or even really and truly scifi, but for some reason it doesn't register as such in my mind.
Then I remembered:
The Matrix. The first Matrix, the one that actually lived up to the hype, before the legacy was tarnished by the (still not actively bad, in my opinion, but not revolutionary as the first was) sequels.
And Terminator 2: Judgement Day. The first was fairly good, the third was fairly bad.
But the Matrix and Terminator 2 were both truly great films, were both truly great science fiction films. They made you think, as all great sci-fi should, they both (or at least Matrix) have revolutionary special effects for their time, as all great sci-fi should, they have compelling stories, logical plots (though Matrix perhaps borrows too heavily from the stupid nonsense tradition of anime and Terminator 1's father twist was perhaps better than any twists in T2). Are they supposed to be just action films? Maybe, especially T2. Do they transcend this and become oh so much more? Absolutely.

and damn it, Han shoots first! ~ Absolutely!

I've never seen Forbidden Planet, but if it's based on Shakespeare's Tempest, I'm sure I'll like it. Thanks for the recommendation.

Also, I'm looking forward to your online reading. I feel like I've been waiting for news on that book forever, but I only read the rest of the series for the first time last January. :)

No, the Star Wars films have aged badly. In fact Lucas' THX-1138 holds up better than all three of the original.

I was a kid and I loved the Luke/Leia pairing until Lucas & Co went and turned it into some kind deviant desire.

Han does shoot first, they changed him from sociopath to cuddly guy-next-door. What????

Yes. Forbidden Planet is still awesome. :)

not a fan of bladerunner are we?

I can't believe you think Alien 3 was horrid. The theatrical release wasn't stellar, but it was David Fincher at the helm and that means he'd have to have tried to make it bad. Check out the director's cut. PHENOMENAL. A lot more to it, including a plot exploration of the guy who's dragged into the infirmary whimpering about "a dragon". (cue suspenseful music...)

I think that you are mistaken. There was no third "Alien" movie. Just like there was no sequel to Highlander and the Star Trek movies mysteriously all have even numbers in their names.

Hooray for Forbidden Planet! And yes, I too think it is sad that the writers of Star Wars aren't nearly up to the standards of some of my other favourite writers. :p

High five, GRRM. High five.

As for Charlie, I've never heard of it, although I love Flowers for Algernon. You have inspired me to check it out, and I thank you for it.

including Day the Earth Stood Still and Blade Runner, but an oldie, but the granddaddy of the space oater, you gots to go with Buck Rogers. The serial, not the remake TV series.

Event Horizon is the greatest and scariest sci fi film ever IMHO

Definitely the original Time Machine, Aliens, and 2001. Excellent movies, all.

what about The Last Star Fighter, Flash Gordon, Star Kid and whoever said DUNE, c'mon even David lynch thinks it was a mistake 9but it's still a guilty pleasure of mine). I understand your reasoning with Forbidden Planet (the reason I love your novels is because your characters are as rich as Shakespearen ones), but the true question is which science fiction is the best. I don't count Star Wars cause it's science fantasy. But there are really three different kinds of science fiction movies: Space odessy's like 2001, Forbidden Planet Star Trek, etc. Then you have your dystopian futures such as Metrpolis, Blade Runner, Gattaca, and my favorite BRAZIL. And finally there are the ones that have to do with Earthlings opening there eyes to science fiction and th future such as The Day the Earth Stood Still, an lets not forget Close Encounters of the Third Kind. Even 2001 fits in this category. So truly what is science fiction.
Serenity was a good movie too. Fifth Element also.
But artistically speaking i think the two best are BRAZIL and 2001.
And when the hell are we going to go back into a science fiction movie cycle again. There hasn't been anything to make us dream of the future. I'm wondering if it has to do with bing in war time because I know that after the Vietnam war Science fiction was big. Maybe horror is the big genre because that's the way of the world now. And we look to the superman genre to get us through it. I just hope the Iraq war ends so we can have a future again.

It's been mentioned, but I'd add Metropolis. None of the sci-fi films that have been listed wouldn't exist without it.

Hello, my comment has nothin to do with fiction movies but rather just a revelation of the way i feel after reading one of the chapters of the third volume of "A Song of Ice and Fire". I know i know, am still in third volume but i was late in acknowledging the talent of GRRM. I must say that am very very depressed. :( after reading the sad chapter in the third volume as u all well know, the incident with the Frey, am not gonna reveal more but DAMN GRRM why did you have to take that decision. You totally took my illusion of coming back home eveyrday from work to read for a couple of hours. Heck, everybody at work knows what am goin through, they laugh at me. I´ve been down the whole day...... Why did you do that????? :( waaaaa. WANT THEM BACK...