1. Alien - "In space no one can hear you scream."
Perhaps the daddy of them all. This one line is the perfect example of a tagline not only directly encapsulating the tone of a film, but also seeking to lure unsuspecting viewers in. The blend of Sci-fi and horror which made the film so unique is cleverly highlighted and the sense of impending doom is really hammered home. It even sounds like a classic horror movie tagline from days gone by, oozing menace and dread. Ultimately, the line seems wholly befitting a film as shocking and tense as Ridley Scott's Alien. Prometheus' tagline was of course "the search for our beginning could lead to our end", which on reflection is fairly vague and uninspiring, which likewise seems wholly befitting a film as......ok you can see where I'm going with that one.