I've bought an awful lot of books just because I liked the cover. I don't regret it. It's like buying an art print that you can pull from your shelf an admire at any time. In this Magenta article, Belinda Lanks asks noted designers about their favorite book covers.
If you ask me who my favorite book jacket designer of all time is, it's Alvin Lustig. If you ask me which of his jacket designs is my favorite, it's impossible. It's most certainly one of the jackets he designed for New Directions' New Classics. Lustig essentially branded the New Direction series with a modern look that was reminiscent of what was going on in the fine art world. It's as if he translated a Calder sculpture or a Joan Miro painting into a book cover. Each book is reduced to color, line, shape, and type to reflect the feel of the book rather than the literal content. The geometric shapes, the bold color palettes, the freeform lines still feel modern today. — Rex Bonomelli