Hardcover? Or paperback? Illustrations? Or just text? First editions? Or you don’t care? Signed by the author? Or not? Lately, of the books I’ve bought, I’ve bought them in paperback—unless I really, really love the author, in which case I’ll buy in hardcover. Illustrations are OK as long as they add meaning to the text. First editions are nice, but I don’t own any of those. I also like signed books, but again, I don’t own many.