Lets face it, Alien is the most influential piece of horror media in human history. If you would care to disagree, than allow me to say this. Alien kicked off the hoards of slasher, horror, suspense, and extreme action in media never before seen. Any piece of these genres post 1979 at least has a bit of influence from it.
Even things outside of the obvious have influence from it. The Halo game franchise has heavy influence from the Alien franchise. Doom 3, often called one of the best suspense games of all time, is so full of influence that it is essentially another Alien experience.
Alien has seeded its way into music, movies, television, video games, and virtually every imaginable form of media. If you have any influence from-
- 80's Slashsers (Friday the 13th, Scream, Nightmare on Elmstreet, ect)
- 80's-modern day horror cinema
- Suspense as a genre of media
- Any horror game
- Syfy as a widly spread genre
Then congratulations! You either have direct, or indirect influence from the Ridley Scott masterpiece.
(Stay the fuck away from Aliens: Colonial Marines and Alien: Resurrection)