The plot twist is one narrative device that can irrevocably make or break a movie. When it works, it can elevate an otherwise ordinary movie to the realms of "classic" status. When it fails, well, you feel like you've just wasted two hours of your life.
The problem is, it's easier to name bad twists than good ones. For every brilliant piece of cinematic tricky there are four or five that totally fail to hit the mark. There are twists that make you question everything you've just seen (in a good way) and those that make you question the logic of the characters you have spent hours rooting for.
The twists to follow definitely fall into the latter category, and take suspension of disbelief to a whole new level. The only real surprise with these twists is that someone thought they were a good idea.
Just try and watch these movies a second time and still be impressed. It's harder than you might think.