The Dark Tower 2 - 4 (4 being the highpoint for me) are all fantastic stories. 5 really drained me reading through. He's a great story teller, but not a great writer, but he does have an enjoyable, easy reading, visceral style. And I do feel that easy readability is an under valued quality. I can't recall most of the titles of the books I have read, but I generally find most of his work (that I have read) enjoyable.