I tried several pizzas of different styles in Rome and while some were very tasty, I wouldn't go back again and again.
The most exiting pizza in Naples was from Salvo:http://www.salvopizzaioli.it/
Unfortunately, it is a bit hard to reach, but worth the effort. I also had good luck in a few very small, out of the way places which I passed by chance and would have a hard time locating again.
On the other hand, I tried the several "famous" pizzas in center of Naples, and was not very impressed by any of them - and some were just tourist traps.
I wonder what else I missed!