Insidious scared me more than any movie in a long, long time. Like lose sleep because of shadows in the corner kind of sleep. This movie was just as good as the first one, if not better because of the story development incorporating the first and even giving you more background information prior to that movie. The going back and forth between the three times was done very fluidly and actually made the movie, and the scary moments, that much better. I absolutely had to pull my hat down so I was only watching the bottom third of the screen numerous times because I was trying to protect myself from shitting my pants. It didn't even help 3-4 times because I still jumped in my seat. The only knock I'll make against the movie is that they did a great job providing closure but then threw on a pointless open ending since there will obviously be a Chapter 3 since Hollywood doesn't know how to leave well enough alone.
I would absolutely recommend anyone that liked the first one see this one. You will not be disappointed. If you have not seen either and like a good scare, you should definitely go check out both of them.