Aliens are among us! But only in fiction, as far as we know. We may one day definitively learn that there is life on other planets or that we have been visited by UFOs. But for now, cinema is our only true window into what it might be like to interact with aliens. It might be our inherent fear that frequently casts aliens as invaders, as opposed to people or races who have their own desires and right to exist. There are stories that explore both extremes, but we feel that the following choices are the best alien movies of all time.
Not into aliens specifically? How about the best space movies of all time? Or maybe the best Mars movies?