I just wanted to share some info on what I found to be the best pizzaria in rome. now certainly that's a tall order, but I found the texture (thin), lightness of sauce (fresh) and excellence in toppings (fresh and tasty) to be top notch.
I am from the states, but my girlfriend is from Rome (I hope that qualifies things), the pizza is so light we even ended up going for a desert pizza after a nice meal at Ferrara in Trastevere.
La Piazzetta - Trastevere
Via Cardinale Merry del Val, 16b
Funghi y Pancetta is the bomb!
ps - if you are in the center Pizzaria Leoncino is quite tasty too. Between Tomacelli and Fontanella Borghese just off Del Corso...