Arrival is a smart sci-fi movie that is far more about us than it is about the aliens. How do we communicate with aliens? How do we react to them? And, very importantly, how do we trust them when we can't even manage to trust each other?
I highly recommend seeing this movie before the twist gets spoiled for you. Well, twists. There are a few. It is one of those, like Sixth Sense, in which the shock is important for the full emotional impact.