If you were to buy one italian cook book what would you buy?

I'm looking to buy a good Italian cookbook but there's obviously loads of choice - I'm not looking for a celebrity chef book (would rather buy an authentic book than a celebrity name!) so wondered what you could recommend! I've had a look and so far am deciding between Essentials of Classic Italian Cooking (by Marcella Hazan) and The Silver Spoon (published by Phaidon) - do you have any feedback/preference for either of these (or any others)? Many thanks!