First of all,this movie is for everybody.Not only for horror fans.And in my opinion,when you want to introduce someone to the monster-horror movie genre,you do a double-bill screening at your own place and you show this movie and Romero's "Night Of The Living Dead".Second of all,this is not only a huge influence on the monster-horror genre,but also the claustrophobic-horror/thriller[Buried(2010),Panic Room(2002),The Cube(1980),Phone Booth(2002),Descent(2006),etc.].And it kind of has everything.
I have a problem,though.I can't decide which is the best thing about the movie.Is it Scott's direction or the scene in which Ripley struggles to throw the alien in space?Well,Scott starts off with these people's daily life on a ship.Everything is nice and smooth.Tension starts to arise when they start questioning themselves,ultimately making us toss and turn.Now that's some good direction.Also,he really doesn't rely on the fact that this is supposed to be a horror movie.In the first hour and 15 minutes,this is more about them dealing with fear.Then in the last 35 minutes,he shows us the monster and everything becomes more alert and scary.
The scene in which Ripley struggles throw the alien into space,is probably the best scene in the movie.First of all,the way it's written is brilliant.Also,this is Weaver's best time to shine given the fact that is the best written material in the whole movie.And the editing is perfect.The suspense grows in parallel with the sound.At one moment it becomes unbeareable.Even after writing this,I can't decide.
Conclusion?A classic and nevertheless major influence on all horrors and thrillers(and more?) to come out of Hollywood in the past 30 years.One to watch.10/10