At LibraryThing, they're talking about the ten books they would save if there were a fire.
Books to save from a fire? It seems like a strange question, because even if all the books burned they could be easily replaced unless it is a rare book collection. Is this question meant to be a variation on the theme of ten books you would take to a deserted island, or the ten books that most changed your life, or simply your ten all-time favorite books to read and re-read?
Take Quindlen's top pick, Pride and Prejudice. There must be ten billion copies of that book in the world. So what's the big deal if one copy burns? It's not worth risking your life to save any book that is easily replaceable.
I apologize if I seem to be throwing water on the fire of this thought experiment.