What movie twist do you believe was so unexpected that anyone claiming to have 'seen it coming' is just a liar

Even after leaving the cinema having watched the Sixth Sense, I was blissfully unaware of the twist at the end. So I guess I'm at one end of the spectrum.

Then there are others who see everything coming. That must be annoying as you'll never get to experience the jaw drop realisation.

But.. what twist do you believe could not have been predicted?