I make several trips a year to various parts of Italy. While I haven't tried every Italian and Pizza place in St. Louis, I have tried all of the well-known locations on 'the hill'. Erio's in St. Peters is by far the best and most authentic. The service is impeccable, and the prices are extremely reasonable. Do yourself a favor and give it a try...you won't be disappointed.
Pros: Service, Quality, Quantity, parking
Cons: Location, not much space