Rex Stout has always been one of my authors and a few weeks ago I started rereading a number of the Nero Wolfe mysteries. Walking into his old brownstone to spend some time with Nero and Archie is like relaxing in a comfortable chair. You have been there many times and you know that you are going to enjoy the experience.
I believe that one of the best compliments you can give an author is to consider his or her books worthy of rereading from time to time. It is even more special to realize that books written more than half a century ago still hold up and are enjoyable to read. Rex Stout is one author, Robert Heinlein (for the most part), Isaac Asimov and others.
Of course, there are books I enjoyed reading that I have no desire to revisit. While I am happy to go back through many of S.M. Stirling's books, I don't particularly care to reread his Draka series. They were good books, but the series as a whole was depressing -- something about having the Bad Guys win in the end, I think. I enjoyed the series and found it an interesting take on an alternative history idea. But it's certainly not a world I would want to live in.
The other nice thing about sampling my inventory is discovering a new author. You see plenty of different books, and if one looks interesting, well what does it hurt to shuffle it off to the reading pile. It may be drek but you may just find a new friend. And after all, one of the reasons I got into this business is that I love to read. I never need to have a shortage of new - or old - books to dive into.