I'm a fan of King (and Peter Straub for that matter). Like Dave, I'm currently re-reading them. I have a thing for that intermediate size between the initial hard cover and the small paperback that I'm waiting for in Canada. For some reason, all my DT books are that size.
Personally, I find the series absolutely fascinating. My wife hates both the aforementioned authors though, because she doesn't have the patience to work her way through the background and detail to get to the scary parts.
I suppose my faves are the DT series, The Talisman and The Stand.
Straub is equally good, IMO at scaring the pants off you.
From the horror genre though, my favorite author would have to be Slade. A Canadian author that bases all the books out of Vancouver and all have an element of the RCMP to them, he (they, actually) is very adept at causing you to sleep with the lights on.
I have a pile of King and Straub books that I would happily trade away for something or just sell for a buck or buck and a half plus the shipping, if anyone wants. I'll keep my faves, but sell the rest. I know it's probably cheaper to pick them up locally, but hey, it's just an offer.