I unrepentantly stand by my assertion that it is the greatest. However, "scariest" is in the eye of the beholder. With humour, people either find it funny or they don't. If they do, it works as comedy. If people find The Exorcist scary (and they did and do, in vast numbers, to vast box office success, etc) then it works as horror. Beyond that, I still consider this an iconic masterpiece, and the greatest horror film ever made.

Great article by the way. :)