If you haven't already, check out the rest of Carpenter's "Apocalypse Trilogy:" Prince Of Darkness and In The Mouth Of Madness.
In the Mouth of Madness is awesomeness trapped in celluloid. Prince of Darkness..... not that great.
I enjoy Prince Of Darkness, even if it isn't his best flick. In The Mouth Of Madness, I agree, is fan-fucking-tastic.