7. Kevin Spacey Goes Uncredited To Keep His Appearance A Secret - Se7en
For most people watching in 2017, Se7en contains just the one main plot twist with its final, "what's in the booooox!" heart-stopper, but for audiences watching in 1995, it actually contained a second twist that came a few minutes earlier: the revelation that Kevin Spacey was playing John Doe, the film's main serial killer.
But why was this considered a twist? Well, at the time Se7en was released, nobody knew that Spacey was even in the film.
The majority of Se7en's runtime is spent with Detectives Mills and Somerset, who are trying to track down the man responsible for committing murders inspired by the seven deadly sins. A big part of the film's mystery and suspense is not knowing who the killer is, since this puts you in the exact same position as the two lead characters.
But if Spacey's name was in the film's opening credits and all over its posters, billboards and trailers, audiences would be waiting for him to show up, practically spoiling the fact that he's playing the killer.
This in mind, it was Spacey himself who suggested that he receive no billing for the film - with his name not appearing in any of the marketing materials or in the movie's famous opening credits sequence - in order to preserve his bloody, shocking reveal.