I've seen quite a few of the more recent critically acclaimed horrors (e.g. babadook) and some of them are scary (e.g. the babadook) but the scariest one I watched in recent memory (e.g. the last ten years) was Paranormal Activity. Shat my keks. Almost wanted to sleep with the lights on after. I don't tend to watch horrors at the cinema. The only one I saw that sticks out in my mind was the Blair Witch Project, which again occasioned a shatting of the keks.