Not sure where you will be in NYC, but these places I have been to cover some different areas of town and styles. These are among the very best places I have tried in Manhattan.
In no particular order
NY Style Slice:
Joe's (West Village) they also have slices with fresh mozzarella worth getting.
Ray's Pizza (Prince Street, Little Italy)
Sacco (Hell's Kitchen) maybe my favorite NY Style slice
Best Pizza (Williamsburg, Brooklyn) another contenter
Sal & Carmine's (Upper East Side)
Patsy's (East Harlem)
Artichoke Basille's (East Village)
South Brooklyn Pizza (East Village)
Joe & Pat's (Staten Island)
Neapolitan Style Pizza 12"
Keste (West Village)
Motorino EV (East Village)
Paulie Gee's (Gtreenpoint, Brooklyn)
Artichoke Basille's (East Village, Chelsea)
Best Pizza (Williamsburg, Brooklyn)
Coal Oven New York-Neapolitan/NY Elite Pies
Totonno's (Coney Island)
Have fun wherever you go!