1. War of The Worlds (Original) Shows all things in nature exist for a reason
2. Enemy Mine Shows that even your most hated enemy is capable of becoming a true friend
3. The Thing (John's version) Shows how trust, loyalty and honor battle for domination

1. The Thing (Carpenter's version)

2. Total Recall

3. Blade Runner

It is too hard to decide on a top 3, so these are just some people haven't mentioned.

The Terminator (1 and 2)

Back to the Future (all of them)

Ghostbusters (all of them)

And acknowledgements for the following, which I feel are necessary for mentioning (and that I can remember that I have seen):

E.T.

THX 1138

RoboCop (1 and 2)

Men in Black (1 and 2)

Jurassic Park (1)

A Clockwork Orange

Hitchhiker's Guide

Starship Troopers

And many more. / Too many to list.

Hard to narrow it down to three but here goes:

1. Aliens

2. Starship Troopers

3. Avatar

Pandorum - Ben Foster is an awesome actor, the movie is scary as all hell, and the ending is great.

Aliens - Already stated. Classic for obvious reasons.

I'm hard-pressed for a third. And I really like Sci-Fi. Maybe Pitch Black? Or Starship Troopers? 2001? Eh. Here's my top 2 1/2, then.

X-men

1 Star Wars Return of the Jedi

2 Star Trek Wrath of khan

3 The Last Starfighter

1. Forbidden Planet.

2.Darkcity

3. Star wars episode six.

Originally posted by Teala

Only two Star Wars movies are any good at all - episode 4 and 5 - the rest just blew chunks.    If you say or  think the rest are good you do not know good story telling at all.

 

1) Forbidden Planet - just awesome...seriously...this movie was way ahead of its time.   I'd love to see a modern remake - not a re-envisioned - but a remake.

2) Alien - nuff said...movie was just awesome.

3) Gattaca -brilliant movie - very scary future indeed and quite a glimpse at what maybe a very real future.

oh

and honorable mention goes to Blade Runner.

Also my number one pick, Forbidden Planet. Amazing how 50 years later, the movie still stands up. I love the sets, wardrobes, special effects in that movie.

The rest is hard. But I guess...

Star Wars, the very first movie, although it's hard to look at it from that perspective after the release of all the others. But when it was released, the sheer sense of adventure it evoked was unmatched. That's kind of dimmed by the release of the later movies which were so bad, but the first one is still a master piece.

Blade Runner and The Matrix tie for third. Two very different movies, but both great. Blade Runner, great performance by Harrison Ford, awesme cinematically, and the dark forboding of the movie. Matrix, mostly for the OMG! action scenes which are still fun to watch.

In no order - I like them all equally.

Logan's Run (WTF people, I can't believe I haven't seen this listed yet)

Enemy Mine

The Last Star Fighter

1. chronicles of riddick (so called critics be damned - best sci-fi in a long long time)

2. starship troopers

3. aliens

These are my three favourite sci-fi movies. Why i like them is because the characters are in focus all the time. There are some other really good ones to, but those focus more on story or effects, example Blade Runner. 

1 # The Empire Strikes Back

2 # Serenity

3 # Nausicaa of the Valley of the Wind (the original versioin)
 

1: Star wars a new hope

2. Star wars Return of the Jedi

3. Star wars The empire strikes back

SW is a pure example of good sci-fi. The "new" ones however ( epidsodes 1,2 and 3) are a load of rubbish. Who here wants to just punch Jar Jar Binks in the face?

Star Wars V

Star Trek: First Contact

T2

1. Short Circuit. It was sci-fi nuff for me

2. Star Wars

3. The Fifth Element

1.  Serenity

2.  Pitch Black

3.  Fifth Element

2 and 3 you could interchange, I'd throw in Men in Black but you people would probably give me the stink eye

I like responding to these topics late because you let everyone else remind you of the obvious favs that you may have forgotten. That being said, and after about 30 seconds of deep thought:

1. The Matrix (I swear every time I'm flipping through the channels and this is on, I end up finishing the movie.)

2. Alien (It baffles me that so many people prefer Aliens. The first movie had such a different vibe with the whole unknown factor that was completely lacking in Aliens. Honestly I preferred the third Alien to the second)

3. I'll give the third spot to Planet of the Apes.

Movies that I'm not sure whether or not they are sci fi, but are worth mentioning:

Eternal Sunshine of the Spotless Mind

The Fountain

A Clockwork Orange

Planet of the Apes

1. Paprika

2. Matrix

3. Returner

Picking my all time favorite was pretty hard considering that I have a hard time watching a movie more than once. There are actually MANY movies that I enjoyed a lot more than these the first time, but can't stand stand watching a second time. The ones I listed above are the top movies that I can watch repeatedly. 

The ones that I probably can't watch again but were much more amazing to me the first time around are:

1. Tron (living in a video game..nuff said)

Tied for 2nd:

2. Terminator (when arnold takes his eyeball out and puts on those shades..coolest thing ever)

2. Total Recall (chick with 3 boobies....the bulging eyes from people being thrown out of an airlock...the tracking booger that arnold had to pick out of his nose...and much more....good stuff)

3.  Back to the Future 2  ( I wanted a hoverboard for years after looking at this film.)

in no real order:

Star Wars

Sky Captain and the World of tomorrow ( I just love the look in it)

Matrix

by the way, when I looked up Forbidden Planet on imdb it looks like someone is doing a new version with release 2013