It has to be Independence Day. Super corny and patriotic but boy I loved it. Still watch it.
And yes I know Blade runner and the likes are cult classics but still Jeeze it was fun.
And did you get the connection in Prometheus which I loved and the replicants of Blade runner. I heard a follow up making the connection is in the offing.
Oh and yes the first Star Wars knocked my socks off.

Alien - 1979 or something and still stands up today...

5th Element

Moon was a pretty good recent one.

Starship troopers, awesome.

The Abyss, Terminator 2, Pitch Black, Galaxy Quest, Matrix, 5th Element, Event Horizon.

[edit] Cant forget Day of the Triffids. Sooo scared of triffids when I was a kid.

I remember seeing 2001 Space Odessy when it came out and I was 19. People were coming out of the theatre going WTF. But I got it ,I think.
Sitting watching Battle Los Angeles and it's pretty good.

Transformers, Firefly, Avengers or pretty much all the marvel movies. Will watch any Sci-fi so to many to list.

"Tron" - the original.

Judge Dredd

Apollo Moon landing on TV was quite convincing,
only rivaled by Orson Welles Martian invasion radio transmittance( with the difference that the second hoax was discovered in the matter of days, legacy of the first last till nowadays)

Worst would be Battlefield Earth. Voted at the 2010 Razzies as the worst film of the decade

FWIW: Just saw Oblivion with the wife and 15yo son. We all really liked it - something different and not what you expect... 8.5/10

Star Wars IV - A new hope
Star Wars V - Empire strikes back
Close encounters of the third kind
Predator
Alien(s)
original Total Recall

^ Hey man, pull your head in. I'm pretty sure Sci-Fi is all about special effects and futuristic looking computer interfaces and sexy chicks in sexy outfits and awesome weapons systems and flying cars and just saving the world with seconds to spare. And explosions. In space.

What you're talking about sounds like actual science imagined into the future interwoven into proper storytelling. I don't know what that's called these days. Probably something like "not profitable".

(you'll like/already know this short story: http://filer.case.edu/dts8/thelastq.htm)

Prometheus was the best sci-fi of late, except that the science sucked and the fiction was dreadful. (that said the overarching idea was excellent)

P.S. NO it was really that bad I've come back for more. The list of dreadful science and fiction is just enormous for that movie. The ones that really stand out are of course the biologist's reaction to a fossilised body, he freaks out, but then not 15 minutes later he's all cute and cuddly with a giant snake-like creature that is obviously in a very hostile threat posture. A biologist. And this being the first meeting with an alien species, setup with what is apparently limitless funding, they pick the biggest bunch of dimwits they could find? I mean, these guys are just plain stupid. The guy who gets lost while his 'pups' are making the map, and have already mapped the way they came, gets lost and then decides this is a good time to get stoned. WTF? And then the other guy gets infected by some alien sludge and deciders to keep it a secret. And then one comes back as a zombie. This is terrible, terrible fiction because the characters are so incredibly unbelievable all I can see is actors spouting bad lines. Not only did it take me out of the illusion it made me groan in embarrassment every five minutes. Besides that why are they there at all based on a handful of 'star maps' in caves anyway? As if that's some kind of evidence of anything.

As for the science. They got there faster than light. That surgery machine stitched her up like it was 1970. Stars move over time and yet the maps in the caves were all the same. They took their ****ing helmets off. What were the maggots, anyone? The scientists kept wandering around opening everything and exposing it to the atmosphere. They took their helmets off. They had a map that even indicated where other life forms were, but they couldn't direct them out of the cave the same way they came in? They took their ****ing helmets off! The architect at the beginning kinda exploded, apparently in some attempt to convey he was seeding a planet with life, but that's not at all how DNA works. And so on...

...oh yeah. When landing on an alien planet and upon discovering an alien construction the crew was all annoyed and perhaps bored and a bit all pissed off with attitude. WTF?

...oh yeah, they took their helmets off. Biologists. Cream-of-the-crop hand picked team to meet aliens first time; yep, let's take our helmets of and breathe. WTF?

...Oh yeah. Protagonist gets an abortion, is stitched up with staples, and then goes running and jumping around the place for the next 20 minutes exhibiting feats of extreme human endurance. And doesn't even bother mentioning "hey, I just had an horrific experience. Help." Nup, just brush it off.

I dunno, there's just simply too much to laugh at. You can go on for hours it was that bad,. It's like it was written by 12 year olds. I hope they get decent writers for the next one.

/coffee.

Dune.

Definitely like District 9, Matrix and Minority Report for the very different/original concepts in them. Especially the Matrix.

Many of the ones talked about above are about people running from an alien, or a "thing" or trapped by a "thing" etc etc. In that sense they are copies of 2001 or Alien
Many are just a slasher/screamo horror movie but with tech/science undercurrent.

To add one to the list, The Island was good

Tron and Dune take me back - they really messed with my head as a kid. Spaceballs would have to be the best all-star-cast low budget scifi sp00f.

Starship Troopers has all bases covered (action/adventure/nudity) and ridiculous story line.