Of all genres, horror films elicit the most varied and complex of responses. There are screamers, and then there are the people who laugh at the screamers — even if they're just as frightened. Then there are the poor unfortunate souls amongst us experience the most unpleasant physical symptoms: the fainters. Yes, some horror films are so frightening and gruesome that they have made people faint. From Psycho to Raw, we've dug up some scariest films that have sent people out of the screening room and straight into ambulance stretchers.