With the demise a year ago of Frankie and Johnnie's on Pearl Street, my vote goes to the relatively new Cucina Bene on Exchange Place.
Their pizza is of the thin-crust variety, with good ingredients in proper balance. I've now had several slices of regular and "lasagna" (surmounted by ricotta and meat sauce), and the quality has been consistently high, within the vagaries of timing and freshness.
Oddly, however, one whole sausage-and-mushroom pie ordered to go turned out to have a thicker, soggier crust and a Famous Ray's-like topping burden. Beware.
The menu also includes freshly-boiled pastas and fancier dinner items, courtesy of CB's relationship to a restaurant in Little Italy, none of which I've yet tried.
Recently, the bored tour guide on one of those double-decker buses creeping down Exchange Place loudly announced "And on your right, the world-famous Cucina Bene restaurant"
Get there before the hordes arrive!