Dune is a cool movie. Of course, it does not do the book justice, but I like the way Lynch envisioned the guild navigators.

As a fan of the novels, I just intensely dislike the way he made changes to the story for no apparent reason. Cutting stuff out, I understand that. That is regrettably usually necessary when converting a novel to a movie, but putting new stuff in? At the expense of even more of the original story? No, uh-uh, I don't get it.

I wasn't the biggest fan of the Dune movie, but i did really like Sci-Fi Channel's miniseries.

Yeah, baby! They Live! "I've come here to kick ass and chew bubble gum... and I'm all out of bubble gum." Gotta love Roddy Piper in that one.
Many decent movies mentioned here. I'll toss in one that I liked that's a rather odd flick: The Navigator.
Another I really like that hasn't been mentioned is The Fifth Element.
Not sure if this fits the category, but I think it does (and I also think it's brilliant): Doctor Srangelove.
Finally, another one that I like is The Adventures of Buckaroo Banzai Across the 8th Dimension.

I love the "Cripple Fight" episode of South Park that does a shot for shot remake of the infamous fight scene between Piper and Keith David (longest... fight scene... ever).

Hmm, do mini-series count for this or would that need a seperate thread? If not then both V & V: The Final Battle, those were awesome. I so wanted one of those laser rifles they had with the clear tube bit in it. They even ended up using them as props on star trek

I agree. But still: the opening scene is quite impressive. The navigators' audience with the emperor, i mean.

I really liked the costumes, models, and sets in the Dune movie, but the way they butchered the story was unforgivable.
*edit* Cogadh, I haven't seen that particular South Park episode. I'll have to make it a point to track that one down.

I liked David Lynch's Dune because he was able to create a strange atmosphere and at the same time convey something familiar (the feudalist system of the empire).
The mini-series, if it had't such cheap effects it would be ok, altough it is closer to the novels.
About they live, you gotta love Carpenter he is able to create original situations. :) And yes that fight must probably be one of the longest one ever seen in the movies, but it also must be one of the more real fights ever seen. No one was knocked-out after a couple of punches.
About the Navigator wich one are you talking about) I know at least three movies with that name, and all of them great.
V is also a great series specialy the scenes where the aliens feed on guinea pigs (or mice i don't remember).
Another couple of movies:
Enemy Mine - with Dennis Quaid and Louis Gosset jr, altough it seems to be made on very low budget it has a certain theatrical feeling and it has a good story.
Explorers - with Ethan Hawke and River phoenix is also a nice movie and it goes along a similar line like the Navigator.
The last starfighter - A very undarrated movie that has a certain appeal. Probably the first movie to use extensive cgi.

Ah, Enemy Mine, definitely an underrated classic in my book... another one for the Netflix queue.
As for the Last Starfighter, it was technically the third major movie to make extensive use of some form of CGI. The first was actually 1973's Westworld (another good sci-fi film), followed by Tron in 1982, then the Last Starfighter in 1984.

I'll add a third vote for "Primer", that's an amazing film. Avoid all spoilers and clear the room of any distractions, though! I'll also put a third vote in for "Dark City", it's pretty spectacular.
Added to that I'll raise you a "Cypher", which is also certainly worth 2 hours of your life.
Some more recent (80s+) Sci-Fi B-Movie favourites of mine are:
Trancers (Time Travel and zombies!... Kinda)
Moontrap (Walter Koenig and Bruce Campbell vs Giant Robots... On the Moon!)
LifeForce (Space Vampires, Zombie apocalypse, Patrick Stewart and gratuitous full-frontal female nudity!)
Krull (Classic Fantasy with lasers!)
Robot Jox (Giant transforming stop-motion mech battles!)
Runaway (Tom Selleck vs. Gene Simmons and an army of robotic spier-things!)
and last, but certainly not least...
Battle Beyond the Stars (The Seven Samurai in Space! With George Peppard, Robert Vaughn, John-Boy Walton, and a female spaceship with lady-parts hanging off of the front!)
(Warning some or all of the above films could be considered as extremely terrible examples of movie making. View at your own risk!)

You have JUST dictated my next DVD purchase!
Also I'd add "Plan 9 From Outer Space" but that really needs to be in a comedy movies thread.
Titan AE was quite good I thought. Then again I'm a sucker for fancy animation, hell I like Final Fantasy The Spirits Within and I detest the games with a vile black hatred I normally reserve for bananas and reality tv.

eXistenZ is pretty good.

maybe it's time to launch gosff.com?
I've been looking for LifeForce for some time now, my eagerness to see it will likely be far larger than the actual enjoyment I'll get when I finally see it.

Meh, Lifeforce is OK. The story is pretty flat and the acting is only passable. Pretty much the only reason to watch it is for the gratuitous T&A.