Not that I've tried it myself, but I'm surprised that nobody has
mentioned Al Forno in Providence, RI given the press it's had here in
the past. Otherwise, here are my favorites:

1) best "Chicago style / deep dish": Papa Del's in Champaign, IL.
2) best "NY style / thin crust":
2.a - outside of NY - Cicero's in Cupertino, CA (assuming the
Laverdi family still runs it)
2.b - in NYC - it's a toss up between 3 or 4 places...
Ray's (the one near Baruch College)
Anna Maria on 23rd street (I think that's the name - top
notch tomato/onion slice)
Dani's in Kew Gardens
Primadonna in Forest Hills (but it depends on who makes it)

3) best "other / untraditional / unusual": Bruno's in W. Lafayette,
IN (for their apple butter and peanut butter pizzas) and Figaro's in
New Orleans, LA (for putting shrimp, crawfish, chicken and other stuff
on their pizzas).

Even if you're some sort of pizza nazi purist who thinks the only
pizza in the world has to fit into categories (1) and/or (2), all of
these places will give you a pie that tastes pretty damn good.
:-Dan