surprise ending?

I would consider surprise ending to be an unexpected twist on the movie at the end.it can be said as like a viewer while watching the movie thinking now everything is about to be finished in movie or viewer is thinking something about the movie and out of nowhere the twist pops up and viewers are surprised.I have seen such twists on some movies like haute tension,the body,malice,primal fear,sleep away camp,usual suspects,the game,the others,saw,the prestige,orphan,the uninvited the vanishing The Crying Game vertigo old boy etc.