Not to flame, but Stephen King is really not that great of a writer, especially after you have read enough of his books to realize that he recycles so much of it, a fact that he himself freely admits. (imterviews and an autobiography) He is brilliant at making a book that appeals to masses, easily read etc, but after I was 16 I couldnt really appreciate anything he wrote, though I did have to finish The Darktower Series and would probably do it again some day.
The Darktower series even reinforces what I have said about King, in the last books he pretty well admits to rehashing plots and characters. He put himself as a character in the book and finishes the epic saga with a: he opened the door and he found himself at page one of the gunslinger. Worse way to end a story in the history of literature imo.