Picking just 3 recommendations is difficult but here goes anyway! Check out Exorcist III - it's a very atmospheric movie with the best "boo!" scene I've ever had the pleasure of experiencing. If you liked The Exorcist, I think you'll enjoy the third installment in the series. My second recommendation is the original Evil Dead. A classic. Enough said. Last, but not least, why not try a Dario Argento movie? Deep Red is a good introduction and is worth repeat viewings. Hope this is of some use.