My fav's
Alien/Aliens
Children of Men
District 9
the Matrix
Moon
Europa Report (I can't remember if I liked it, just that it was worth a watch)
Labyrinth (Fantasy, but that's ok)
Star Wars (duh)
Inception
Prometheus - I know it got a lot of hate, but I tried to look past that and just enjoy it. I like that they're pretty much at an alien armoury.
The Abyss
Tron
Cloverfield
I.Robot
Contact - Only because the book is fantastic
That's all I can think of for now,
Honorable Mentions
Pacific Rim
Terminator
Star Trek (new)
Gravity
What about books? I'm very picky with my Sci-Fi books. There's a lot of crap to sift through. I just finished Red Mars, and Green Mars by Kim Stanley Robinson and they are fantastic. I also suggest the Hyperion Cantos by Dan Simmons as well as Illium.