I thought the movie was extremely lacking.
Occasional humour and realism was good, but not enough to save it. To me, the movie only seemed to work on one level which was scares. It just didn't scare me and then it felt like it had nothing else to offer.
SPOILER ALERT!
I love good ghost stories and in my favourite haunting-films, the ghosts have a proper story. Sometimes they're even characters in their own right with personalities/agendas. The entity or whatever in Paranormal Activity was just
something, you never really knew what it was trying to accomplish or why .. or even what it was.
Some may argue that this makes it spookier, but as I said, I wasn't spooked anyways, so ..
In my opinion, good horror films usually offer way more than this one did. This one felt like it didn't even really have a story, just unexplained stuff happening at night. And this gets hyped as an awesome horror flick? Blah. If you wanna see a recent good horror film, I would recommend "Drag me to Hell". Aside from realism, it's got tons more to offer and is just way more entertaining.