Insidious

Well this isn't quite like "Paranormal Activity" even though it's got some of the same names behind it.  This is a good thing, as the documentary style of horror movie is mostly played out.  This one is a straight up make you jump film.  Music will swell up unexpectedly.  Faces will suddenly loom from behind main characters.  Hands will come in from the edges of the film to grab our poor unsuspecting victims.  All of which is designed to make us catch our breath and jump, or jump and catch our breath.

The plot is pretty much in the trailer.  Family is worried about being in a haunted house, but it turns out it is their son that is being "haunted."  There is the concerned father and mother, and the brave researchers of parapsychology on one side.  On the other is a host of ghostly beings that don't seem to have anything linking them.  From ghostly kids to frankly terrifying demons.  They all seem to want the boy for some reason. 

Definitely well worth a watch if you need a good scary film!