Peking Duck House on Mott is a winner. Although I'd have to say that all of their other dishes (like the ones included with the Peking Duck dinners) are a notch lower in quality than similarly priced places around the city. Be sure to ask for the carcass to take home; there's just as much meat left on there as you get carved at the table.
If you end up uptown, Chef Ho's Peking Duck is great, too.
720 2 Ave (89th St) New York, NY 10128-4411 - (212) 348-9444
Their default is to roll the duck for you tableside, but they're happy to let you do it yourself traditional style.