The NSOG isn't really a book about star-hopping as such but it is the best reference for DSO observing currently available. Star-Hopping: Your Visa to Viewing the Universe is mostly text.

Alan MacRobert's book is similar to Celestial Sampler and is highly recommended. I did all of his star-hops, which first appeared as articles in Sky & Telescope, many years ago and enjoyed them very much. I had hoped that a second volume would be published but that never happened.

Dave Mitsky