Where is the US's best pizza?
Welcome to the runt of American pizzas. Chicagoans, in particular, delight in making fun of the notion of "St Louis pizza", but it exists and, dang it, it is pretty good.
"St Louis pizza" is a round thin-crusted pie cut into square slices, of all things, and with a heavy dose of "Provel" cheese. Depending on whom you talk to, Provel is a local source of pride or contention; the creamy blend of Swiss, provolone and American cheeses are not really available anywhere else (perhaps for a reason). A pizza expert over on the website Slice swears provel is evil: "It's as if the cheese knows to wait to scald the roof of someone's mouth before it decides to let go of the heat."
Imo's is a huge St Louis institution and likes to claim making the square-shaped slices first (borrowing a founder's job as a tiler).