This is a tough question, as I love both. Paperbacks are eminently portable, but hardcovers are so much sturdier. Paperbacks sometimes have a greater sense of history, but hardcovers smell better. In a perfect world, I’d have each for its appropriate purpose. Fancy editions (Complete Classic-Author, for example) would be hardcover. Longer books would be hardcover. But quick reads would be paperback. Guilty pleasures, also paperback. Plays, paperback. But I certainly wouldn’t want ALL my books to be paperback.
What about you?