prometheus (2012)

"This place isn't what we thought it was."
When a team of scientists find clues to what they think are the origins of mankind, they are prompted to journey to a forbidding part of the universe to find the answers. Little do they know what monstrosities are awaiting them there, or who is funding their trip.
Spectacular and dumb sci-fi, where one has to accept that we can develop spacecraft and techniques to travel vast distances through space, but can also neglect the most basic of hygiene and safety procedures.

alien (1979)

"Ash, that transmission - Mother's deciphered part of it. It doesn't look like an S.O.S."
A routine mineral transporting job for the crew of commercial towing vehicle Nostromo, is interrupted when the Company intercepts a signal from a deserted planet and orders them to investigate. What they find is an alien spaceship full of eggs, and Kane (John Hurt) is attacked by one of the parasitic eggs they then realise the signal is a warning. With Ash (Ian Holm) overruling Ripley (Sigourney Weaver) and letting the crew members who were attacked (and the alien) on board their ship, the hunt is then on to find and kill the alien. But then the crew find out that they are dispensable, and that the Company has plans for this alien lifeform.
A tremendous piece of work from Ridley Scott, brings a real sense of tension to the cat and mouse games. So much so it spawned three sequels.