Italy has many providers and generally the price of all of them is similar, its less than €30 in general for broadband and landline.
Some of the tested ones are.
One of the biggest providers. Covers all of Italy, also offers TV services as well as phone and broadband. Mobile is not the cheapest but coverage is great.
Is simple to use, covers the whole of Italy, they have lots of shops if you need help, and customer support is ok.