The Best King novel is probably "The Stand" it's just an incredible part of modern literature. The foreward for the newer editions is hilarious to me. King talks about the publisher cutting a ton out of the manuscript (I don't have my copy in front of me, but it was something like 100,000 to 150,000 words) as it was only his third book he didn't have the clout he enjoys now. With the re-printing he put all that back in, because now he's Stephen freaking King.
Books and Horror media in general don't really scare me, but if a book came close it was "Pet Sematary." The ending captured perfectly what most people would do in that situation. No matter how many times you see how badly that decision is going to turn out, you can always convince yourself there's a chance. That's the scary part of that book.
Most recently I read "Duma Key." It was decent, with the characterization you come to expect from his work. It definitely suffered during the ending though, and resembled some of his previous work a little too much.