Bond...James Bond wrote:what's the diff between science fiction and fantasy (is there one?)
The difference is the "handwavium" the use to explain how they break the laws of physics.
Science Fiction uses, well, science, or at least the appearance of science through some sort of ubertechnology. You've got everything from stuff that is actually doable, like Clark's "2001" tech (where the technology is scientifically possible, we just haven't gotten around to having an engineer build some of it yet), to extreme tech along the lines of Starwars hypermater reactors and hyperdrive "handwavium" devices.
Fantasy used the supernatural, be it spirits, magic, or mythological creatures. The Lord of the Rings is a great example of this, where you've got dragons, magic swords, and a few very badass wizards blowing stuff up.
But then, I like how Clark put it... "Any sufficiently advanced technology is indistinguishable from magic."
Now for my list...
1950s: Toss up between War of the Worlds and The Day The Earth Stood Still. Both are classics, both have some very memorable moments, but TDTESS has one of the all time best lines... "Klatu Barada Nicto!"
1960s: Planet of the Apes. 2001 was a great movie, but it bores me to death. I've never been able to watch 2001 in a single sitting as it makes me fall asleep. But Planet of the Apes... "Damned dirty apes!" Or as Jay said, "In this dark future it is not we who will spank the monkey, but the monkey who will spank us!" Snoogans...
1970s: Starwars. Anyone that disagrees is a communist and probably supports the Jihad. Alien comes in as a close second.
1980s: The 80s produced entirely to many Sci-Fi flicks thatw ere created from pure, distilled awesome for me to choose just one. I mean, you've got Empire Strikes Back, Return of the Jedi, Blade Runner, The Terminator, Aliens, Predator, Repo Man... The 80s wasn't just new wave pop and goofy haircuts, it was awesome sci-fi and badasses with laserswords and guns.
1990s: The 90s produced a couple of good ones as well... Let's see... Predator 2, Total Recall, Naked Lunch, Terminator 2, and Stargate. Of the batch, toss up between Stargate and T2.
2000s: So far this decade suchs the balls for good Sci-Fi. It's all popcorn movies like Space Cowboys, boring hard-SF like Mission to Mars, remake schlock like Planet of the Apes/War of the Worlds, and mindnumbingly stupid abuses of scence chicklittle flicks like Day After Tomorrow and The Core.