Better Twist Ideas
A BUNCH OF SPOILERS
Signs- It's revealed that his wife was an alien that returned to earth to reveal that the daughter was 1/2 alien.
The Village- It's revealed that it takes place in the future, On a crater on the moon in a dome.
Lady In the Water- The creature that takes the lady is Paul Giamatti's ex-wife
The Happening- It's revealed that M Night's character wrote the film and then dies from the toxins. It's also revealed that the Toxins intentionally make you dumb.