9. There's A Second Climax - Speed
Speed is one of the greatest action films of the '90s, no doubt, making the absolute most of its ingenious high concept, where LAPD cop Jack Traven (Keanu Reeves) attempts to stop terrorist Howard Payne (Dennis Hopper) blowing up a commuter bus if it drops below 50mph.
Though there's never much doubt that Jack will eventually find a way to save everyone onboard, the trailer unapologetically spoils that there's actually a lot more movie to go after that.
Beyond showing a shot of the bus colliding with a plane and exploding while the evacuated passengers look on, there are also several clips of Jack and Annie (Sandra Bullock) onboard a derailing train.
You needn't be a particularly observant viewer to appreciate that this spoils both the film's false climax and the additional final showdown between Traven and Payne on a subway train.
Considering how anyone who didn't see the trailer would absolutely expect the film to end once the passengers were rescued from the bus, the trailer needlessly gave away a surprising sting in the narrative's tail.
Is a bomb on a bus really not enough to sell a movie? Did they need to give away the secret second climax too?