Scary Movie...
Last week The Shining was named the perfect scary movie according to boffins at King's College, London. The formula they used to work this out was:

(es+u+cs+t) squared + s + (tl+f)/2 + (a+dr+fs)/n + sin x - 1

Where:
es = escalating music
u = the unknown
cs = chase scenes
t = sense of being trapped
s = shock
tl = true life
f = fantasy
a = character is alone
dr = in the dark
fs = film setting
n = number of people
sin = blood and guts
1 = stereotypes "