Strijkbout: Nightmare On Elmstreet is the more Haloweenish horrormovie.
The Exorcist is more religious of tone, like The Omen.
Lol :) In my opinion, The Omen was a cheap attempt to cash in on the hype of the great religious horror films that are The Exorcist and Rosemary's Baby (and maybe, to a lesser extent, The Wicker Man). Everything that The Exorcist did right, The Omen butchers, IMHO...
darthspudius: I do agree but at the same time, this is the first chance I have to see two of my favourite horrors in the cinema. As someone who still appreciates seeing classics on the big screen I cannot pick between the two. :P
Strijkbout: If you want to see a classic, I agree with ichtyandr, go see The Exorcist. =)
I second Strijkbout's recommendation to listen to my recommendation :) Go see The Exorcist!