I'm sort of a pizza nut so I have been going to every pizza place I can find in FFX County.
This is the best in my opinion - Emilio's Brick oven in Sterling -
http://www.shopsterling.com/business/emilios/ (They close week nights at 8pm... yeah I know WTF?)
Runners ups-
Church's pizza Vienna: B+
is good but I didn't care for the crust. A little soggy from me, but the place is always packed and people rave about it.
Tony's Pizza in Fair Oaks: B+
I really liked this place better than Church's. Get rid of those scrolling plasma screen menus. One minute I'm reading the selections and the next minute the menu vanishes!
Mediterranean Cafe in Herndon - The old Sylvano's -
Great pizza, great sauce, a little spicy but loaded with toppings!