I have recently discovered Pizza Napoli, in calle Pradillo, 14, where they make the best pizzas I have tried Madrid.
Their pizzas have been created with the help of Pizzaiolo Masters from Napoli, using authentic ingredients straight from Italy, like Caputo flour and La Torrente tomatoes, which they import from Napoli, and the authentic fresh mozzarella of Latticini Italiana. They are prepared and cooked on demand, and the dough is stretched and worked by hand, without rolling pin, or any industrial process or product of any type.
Their restaurant is really small, just a cople of tables and a bar, not really that great for eating in, so it is best to order them to go, either by phone or directly on their webpage. Their delivery areas are the Chamartín District and some parts of Arturo Soria.
Try them if you get a chance, they are absolutely spectacular!