To have a favorite book by Barbara Guest (Reality Street Editions, 1999) one must first know who she is. Then, you must have read at least two books by her, like at least one of them, and then you must feel strongly enough to have an opinion, and feel that that opinion is relevant to someone else. I know I translated two poems from this book and published them in Spain, at some point. I once spent considerable effort collecting her books, reading them all and having opinions about them. I still value that experience, and the volumes I collected, returning less frequently. I learned what I needed to from her.
My countdown is skewing toward women writers, for no particularly good reason.