Movies are such a prominent form of media these days, yet most movies are predictable these days. Here are a few awesome scenes that bucked the trend and threw the audience for a loop.
"I am your Father" in Empire Strikes Back
The grandfather of all 'holy shit' movie moments. No one saw it coming at all. It even went as far to define the remainder of the series, spawning three prequel movies and adding a ton of emotion to the final light saber battle in Return of the Jedi between Luke and Vader.
"The truth is... I am Iron Man" in Iron Man
The ending to the first Iron Man movie was all set up. Iron Man had his origin story and the public knew about him being a hero. All that needed to happen was Tony Stark had to tell one little white lie, saying he wasn't Iron Man. But the final last lines in the movie show off Tony Stark being the bad ass he is and telling the entire world the truth. This was taken out of the pages of the 500th issue of the Avenger's, in which Tony Stark reveals he is Iron Man in a press conference while under a mind control spell. While the context isn't exactly the same, it could have just been a clear cut ending.
The T-Rex saves the day in Jurassic Park
All hope was lost. The velocirapters had everyone pinned in the corner. Sure, the protagonist always come out alive, but it typically isn't by the hands, or in this case claws, of something that the protagonist ran from earlier in the film. The T-Rex even gets it's own 'hero shot' as the banner in the visitor's center drapes over him as he roars at the screen one final time.