Just discovered this lovely little pizzeria on Chiswick High Road this year and now I'm a regular customer. I usually go for home delivery but was passing the other day and stopped in for a quick bite with a friend, it was quite Italian, bustling and fast service, I think they expect you to eat and run which is fine as that was exactly what I had planned.
The pizza toppings are definitely the best I've found in London. they managed to be innovative and yet still very italian. The dough is good, thin and traditional,t he ingredients are high quality and tasty and not over-loaded. If you're a pizzahut / american pizza fan then this might not be for you but I'd definitely recommend for the discerning piza eater!
Try the Skinny, the Buffalina or the Spinachi with one of the side salads- all delicious and generous portions!
Firezza serve a variety of pizzas with a choice of toppings to eat in or take away. They also offer a delivery service.