I tend to pay attention to what the critics say... if you've not seen this site, it's great. they add up all the critics say on the movies, almost 300 critics total on the web and in papers and they even link to a lot of those reviews
Rotton Tomatos
This for me seems like a renter. Besides its nice to watch scary movies in the comfort of your home, so you can duck behind your couch for the really scary scenes!
