2) Signs (2002)
The Story: Disillusioned former priest Graham Hess (Mel Gibson) is struggling with the death of his wife when inexplicable events begin to unfold around his Pennsylvania farm, including crop circles and violent animal behavior. Unnerved by mysterious beings prowling the nearby cornfields, Graham begins to question his own sanity, only to learn that similar sightings have been occurring with increasing frequency around the world. Faced with what he sees as the end of days, Graham attempts to protect his family from extraterrestrial invaders.
The Twist: The antagonistic aliens would be totally terrifying, if it were not for one small detail: water (you know, that nifty little chemical compound that makes up approximately 70% of Planet Earth) is absolutely lethal to them. And yet, these supposedly super-intelligent beings surmise that one teensy obstacle like that is no reason not to go ahead with a full-on invasion of Earth.
Needless to say, their plan is a colossal failure, and the human race quickly repels them. Also in the running for worst twist, seemingly useless phrases from Hess’ dying wife turn out to be somehow essential in defending against invading aliens, and God not only exists but apparently spends all of his free time setting up convoluted plans to take care of Mel Gibson.
Why It Sucks: After building an almost unbearable atmosphere of suspense and tension, writer-director M. Night Shyamalan unequivocally drops the ball with an ending that insults the audience’s intelligence. By making the aliens’ weaknesses something so mundane and face-palmingly silly, he unravels any credibility the movie could have had as a sci-fi thriller. Also, no self-respecting viewer could ever buy that God would tell a little girl to leave half-filled glasses of water around the main character’s house in case of an alien invasion instead of doing something divine like, you know, making it rain. For a film as spookily effective as this for its first two-thirds, it’s a real shame that Shyamalan’s script couldn’t stick the landing.