Phoenix has pretty slim pickings when it comes to good pizza, or at least pizza that I'm accustomed to. Rosati's, while not quite what I'm used to, is the best representation of Chicago style pizza that I've found.
The Chicago style deep dish is good. The toppings, especially the sausage, are plentiful and tasty and the sauce is good. I think the crust is what is a bit off.
Overall, Rosati's is still my choice for pizza in the valley.