I heard the Japanese version of The Ring is very scary, scarier than the English version...but I didn't watch it because I don't like scary movies....they scare me too much...
You could watch the Omen the newest one that came out, not the old ones...I heard it was really scary.
And The Amityville Horror the new one not the old because that movie is really scary...I did watch it I couldn't sleep for like weeks it might not be that scary to you, but it creeped me out...
I heard those Exorcists movies are scary too..I never watched them before but I heard from my friend they were scary...
WHATEVER YOU DO Do NOt Watch "Hide and Go Seek" it was so boring...probably the most boring movie of them all...it was rated R but it wasn't even that scary so don't watch it, only all the action is at the end and it was weird.
Japanese horror movies are always excellent, in contrast to the always lame western version (stop ruin great horror movies!) which makes you wonder how they always get away with it. I recommend watching Ju-on (The Grudge) as it's very good.
And The Amityville Horror the new one not the old because that movie is really scary...I did watch it I couldn't sleep for like weeks it might not be that scary to you, but it creeped me out...