A nice local find is Flippin Pizza that just opened recently in Falls Church. The cozy modern neighborhood pizzeria offers decent New York style slices. With deals like two slices and a drink for $5.50, its hard to pass up and a good alternative to Z-Pizza.
It is tucked away in the corner of the atrociously decorated "Flower Building" on Route 7 and very easy to miss. They don't deliver, but they have a call-ahead-and-pickup service available.
Local blogger Blueweeds did an excellent review of this pizzeria recently too. Its getting good reviews on Yelp too.