7. The Fly- "Be afraid. Be very afraid."
Surely one of the most re-quoted taglines in film history. Viewers may not have known exactly what was about to unfold when they first saw the movie as the poster cleverly doesn't give too much away. However this wonderfully ominous line would undoubtedly plant a seed of fear in the audiences' mind as they began to consider what exactly they should be afraid of. The Flys less-is-more approach to the tagline game worked a treat and as Jeff Goldblum slowly morphs into that sickening monstrosity before your very eyes, you can't say they didnt warn you!