What movie or TV moment, the first time you saw it, was the most jaw dropping, blown away, unanticipated thing you have
ever seen?
This might be weird, but for me it was finding out Bruce Willis was already dead in Sixth Sense.
Also, I knew about it already on seeing it, but others have told me the end of Seven was a jaw dropper for them.
The last few minutes of Memento were pretty surprising to me as well.