The Horror Challenge,
An effective jump scare.
I almost never scare from a jump scare, but the movie that I did scare was 100 Feet. The moment when Famke Janssen is lying in her bed, and light a cigaret (I believe) and then a ghost appears. Oh I'm convinced that my heart run to my ears somewhere. Other movies that I have effective jump scares are those found footage movies like paranormal activity, but that mostly because you know that something will happen, so you tensed as hell, and when it happens, well.. you have a jump scare. But 100 Feet was different because I totally did not saw that coming.
My boyfriend though, he scares from EVERYTHING. (He will even scare from Cartoon Network shows, seriously) So it's really depending on how sensitive you are for jump scares.