Over at Slice (the pizza blog!), Adam Kuban has compiled a list of all the different pizza styles found in the US.
Once the Italian immigrants brought their Naples-style pies to the States, it evolved a bit in the Italian neighborhoods of New York to something I've seen referred to as "New York-Neapolitan." This is basically what all the coal-oven pizzerias of New York serve. It follows the tenets of Neapolitan style in that it's thin-crusted, cooked in an ultra-hot oven, and uses a judicious amount of cheese and sauce (sauce which is typically fresh San Marzano tomatoes, as in Naples). It deviates from Naples-style in that it's typically larger, a tad thinner, and more crisp.
There's a surprising number of styles.