Ok, you guys got me in the mood for making my own list, as I'm a massive sci-fi fan, I'm going to have to make a top 20 (could easily stretch to 50 but I don't want to put you guys through that lol).
So here goes:
1. Terminator 2: Easily the best combination of sci-fi, action and story ever put into a major blockbuster. Everything about this movie screams of "yes, I want more". I'm constantly blown away with the execution and scale of this summer blockbuster which is more than just that, it's a great science fiction story and like the best in the genre, it never fails to miss the mark.
2. Star Wars Ep V: The Empire Strikes Back: The pinnacle of Lucas' saga is darker and grittier than the original and a better movie overall. From all the great one liners to the great action set pieces and the terrific story arcs of it's characters, this delivers in almost every department.
3. The Matrix: It didn't quite become our generations Star Wars as some expected but the original is easily one of the most influential science fiction movies of the modern era. The techniques used in filming it went on to define almost every other action movie trying to strike it big for almost a decade. The story is typical sci-fi fare, of humanity getting to big for it's boots and paying the price but the execution is wholly unique. The dialogue is terrific, the philosophy sometimes pretentious but none the less interesting and the characters live with you forever.
4. 2001: A Space Odyssey: Al, the computer is often imitated, from the Simpsons to the recent Oblivion and you know what they say, imitation is the sincerest form of flattery. Some of tropes used in this movie have been copied by film makers in the decades that have followed and few films are as influential. It's also a poignant message of our own failing humanity, more relevant now than it ever has been in the past.
5. Inception: Some of Nolan's finest work and a true modern classic, these weaves all the complexity of previous 20th century sci-fi blockbusters such as The Matrix and the smart action of T2 and the Bond franchise. In doing so, it crafts something new and at times better. Nolan is the master of creating intelligent blockbusters and does it here with an ease and flair that I didn't think possible after The Dark Knight, his pièce de résistance.
6. Laputa: Castle in the Sky: Studio Ghibli doesn't get much better than this sci-fi epic for all the family. There are the typical themes of technology versus nature and the thrill of air travel but all of this is woven between a very beautiful relationship between the two main protagonists, a princess and a mine worker. The simplicity of it's characters love and care for each other elevates it above other, similar sci-fi adventures with the familiar cliched lost cities, pirates and evil government officials.
7. Aliens: Not exactly superior to the original but just something which I enjoyed watching more on repeat viewings. If I was given the choice of choosing one or the other to watch forever on a desert island, I'd pick the Cameron actioner everyday.
8. Children of Men: As sombre and sad as science fiction can be, this movie depicts a depressing world where mankind can not reproduce...except one last pregnant woman. A young girl in fact, the Mary of this movie, who must be protected by Clive Owen in his best performance to date. In fact, the whole cast provides us with some of the best on screen performances seen in a long time. A beautiful, sad and at times up lifting movie which typifies the genre at it's best.
9. Brazil: My introduction the the wild and wacky world of Terry Gilliam took me totally by surprise. This is an absurd movie set in an absurd world with absurd characters and yet it somehow works and works very well. Gilliam is a terrific worked of illusions, creating a dreamy, dystopian future of bureaucracy, formal suits and flying men. A must watch.
10. Alien: A great sci-fi/horror combination which gave us the Xenomorphs and they have never been as deadly and as terrifying as they were in the original. This was science fiction which seemed to be a complete opposite of the likes of Flash Gordon and Star Wars. There were no great empires and no great heroes, just a terrified crew of miners on an intergalactic mining ship and a cat.
11. Blade Runner: A cult hit which flopped on original release, this movie has gained in stature of the years. There are a lot of versions but no matter which one you watch, they all give you something to really sink your teeth into. This is a thinking man's sci-fi.
12. The Terminator: Wasn't sure where I was going to place this, it could easily have been a top 10 but I think Alien and Blade Runner bring a bit more to the table. It is however, one of the best suspense thrillers ever made and the sci-fi seems like a backdrop to the horror that this young woman must face, as she tries and escape the unstoppable killer.
13. Jurassic Park: Wasn't sure if I should rank this as sci-fi but then I thought, making dinosaurs on a planet as part of a theme park attraction, that's about as sci-fi as things get. From the moment the dinosaurs are revealed to the famed car and T-Rex scene, this movie had me gripped. Steven Spielberg created a sci-fi masterpiece
14. Independence Day: This gets way too much abuse. ID4 is easily the best straight up alien invasion movie ever made...by a country mile.
15. E.T.: Didn't quite like it when I first saw it, maybe it's because I had my older brother constantly nattering away but on watching it again for the second time, I was probably 12 or 13 at the time, I fell in love. The characters, the story, the struggle...I almost welled up when the bikes started flying. This is how children's sci-fi should be done.
16. District 9: The Office meets ID4...I kid, this is far more than that. Not just a simple science fiction action movie, this is a study of human nature, our acceptance/hatred towards those who are different. Not exactly original themes but execution was unique, as was the setting and the truly heart breaking story which encompassed it all. Add to that some very cool weapons!
17. A Clockwork Orange: not an ordinary sci-fi and definitely not an ordinary movie. It's difficult for me to tell you how this made me feel, after the first viewing I wasn't even sure if I liked it. Could I root for the characters? Was it right for me to do so? Then again, aren't the best movies the ones that make you feel, whether it be tension or apprehension or repulsion.
18. Minority Report: It's that darn Spielberg again, in possibly his most adult and unforgiving science fiction adventure yet. can humanity predict the future and if it could...how accurate could it be? That's a question that is never fully answered in this movie but it doesn't have to be. This is more about the journey than the destination.
19. Starship Troopers: Big, loud, funny and at times thoughtful, this deserved a full blown, big budget sequel. This is typical Paul Verhoeven and I love it.
20. Wall-E: Beautiful, tender and a stark warning to us all, this is a family film with a deeper message. And even when the beauty of the robotic characters is interrupted by the some what annoying humans, I just can't help but smile at the most unlikely of romances...oh and did I mention it has space travel, robots, a destroyed earth and a futuristic space colony of humans? It is sci-fi after all.