Here are a few more to consider:
Carlo Middione has a couple of cookbooks that I like a lot. Everything I have ever tried from Food of Southern Italy has been wonderful. The same goes for La Vera Cucina, although I have not cooked as much from that one.
I also am a big fan of Lynn Kasper. The Splendid Table is a classic that focuses on Emilia-Romagna, in northern Italy. The recipes are relavatory. There are great explanations to explain and put the food and recipes in context. The Italian Country Table is also quite good. Like Middione's second book, it does not stick to a single region but rather features everyday uncomplicated cooking.
Here is a third suggestion, but only if you are up to searching for a used copy and don't mind recipes that, while not complicated, are brief and do not hold your hand. Ada Boni's Italian Regional Cooking is the book that opened my eyes to Italian cooking when I was just starting out. My copy of Hazan's Essentials came later! I love Hazan's cookbooks but this gem covers so much more territory, almost literally. The recipes come from all over Italy, not just the regions we are most familiar with here where I am (in the US). So much was new and unfamiliar to me and now, still, many years later, when I open the book there seems much to discover.
Buon appetito!
(I hope I spelled that right. :))