Recently, my daughter asked me to read The Lord of the Rings to her before she goes to bed each night. As it turned out, this was a serendipitous request, as I was planning to begin re-reading it myself, as I try to do every year or two. The Lord of the Rings is one of those books I feel the need to return to often; my appreciation and enjoyment of it increases with every re-reading. The same is true of many of the stories of H.P. Lovecraft, Clark Ashton Smith, Robert E. Howard, H. Beam Piper, and Poul Anderson.
This made me wonder: what are the books or authors you return to again and again and find that you enjoy more each time that you read them?