Couple of suggestions:
Paranormal Activity: 1 is done well, 2 not so well. Creates a spooky atmosphere using sound (or lack of)
Don't watch The Mist: epic fail.
Trick R Treat is great for Halloween though not scary.
Texas Chainswaw Massacre, Last House on the Left, I spit on your Grave, Night of the Living Dead. All good movies but only watch the originals. Remakes are shit.