If I were to have a literary idol it would be King.
First book I read by him was Tommyknockers and I was hooked ever since.
Rose Madder, Insomnia, Talisman and Black House (?) have some very nice Dark Tower tie ins.
Any of his short story books are terrific (Graveyard Shift, the Bachman Books, Nightmares and Dreamscapes, Everything's Eventual, Skeleton Crew)
Bag of Bones was a touching novel along the lines of the Green Mile with a small touch of supernatural in a character-driven atmosphere. Eyes of the Dragon was incredible for its innocous touch (and also more tie ins).
I still haven't read the last two Dark Tower books, the Girl Who Loved Tom Jordon, Gerald's Game (Started it but didn't get far), Delores Clairborne, or (strangely enough) Pet Semetary. Never heard of Colorado Kid till this post so thanks!