If you're near to the Parliament station end of the city you'll need to check out Liverpool street. It is by far one of my most favourite areas of the city due to the great restaurants and bars. SPQR make what I believe are the best pizzas in the city (bold claim right!).
SPQR use fresh ingredients on the pizza, the cheese is delicious and what tops it off is the dough! The dough is incredible! All of the pizzas are produced in their traditional wood fired oven.
The pizzas come in two styles, red and white. The reds have tomato sauce and the whites do not. My favourite red is the Gamberi and my favourite white is the Zucca. They usually have a couple of specials each day also.