depends on what you think is scary. my mom is like this super catholic mexican woman so shes terrified of devil movies like the amittyville horror (sp?) but i just saw a movie called a haunting in connecticut that was pretty sketch, but nothing super scary.
It was good, but not that scary.
I know this isn't what you asked for, but I would reccomend you watch The Thing (1982). If you liked Alien, you'll probably like it.
Yeah, it came out in 1980, but if you want to be scared shitless, watch The Shining.
In the dark.