The Silver Spoon from Phaidon Press (Google it for several sellers, including Amazon). With 2000 recipes on 1199 pages, it's a well organized bible of Italian cooking, first published in English in 2005. It's been Italy's best selling cookbook for more than 50 years. It includes everything from classic sauces to savory soups, meats, fish and poultry to all sorts of veggies, pasta dishes and desserts.
I've had it for 4 years now and I've barely scratched the surface. Every time I randomly open to a new page there are 2 or 3 different and delicious recipes to try.