I've always loved Dune, but there is a lot of good scifi movies.

Any of the Star Trek movies.

R.

all of the Alien movies. Some were a little dark, but they were all awesome!

Definitely Serenity. I am a huge fan of Firefly. When I watched Serenity, I was tripping. Exactly when River jumped through the doorway and went kicking ass, a huge block of the ceiling decided to detach and crashed into the floor with a horrible noise. Awesome :D

Alien would have to be my all time favorite. Ridley Scott's version was more of a thriller but I like the action sequences in the Cameron sequel.

Preadator

Spider man
Riddick - thumbs up:thumbsup
Star wars - i do agree in this one also
War of the Worlds? I just thought so, but the ending wasn't that good..:(

Star Wars
Independence Day
Lost in Space
The Matrix series