Another vote for Dark Star as possibly the best b-movie ever.

Wasn't it John Carpenter's first outing? I seem to remember that it was made for $60k, but despite the Alien pet that was spray-painted inflatable beach ball with claws, it was hugely entertaining and a cult classic. Script was very funny.

I also remember Carpenter's 'The Thing' as being a very enjoyable Sci-Fi/Horror romp..

Blade Runner Director's Edition is also right up there IMHO.

Dune was a surprisingly good interpretation, provided that you had read the book beforehand - you would be completely lost otherwise!.