Great article on all of the different types of pizza found in the US:
Slice: A List of Regional Pizza Styles
I wonder if Canada has any regional styles? Most of the pizza I've had in Canada is national chain, ie. Pizza Pizza, Pizza Hut - and out east here we have Pizza Delight (which is a nice little restaurant, but their pizza is horrible - who would associate their name with "delight" and then proceed to provide such horrible pizza???) and Greco's, both of which have inspired us to make our own...
If anyone has a good midwest/Chicago thin crust recipe I would LOVE it! Those are the pizzas from my childhood.