Flex Mussels
Flex Mussels has been killing the seafood game for the past few years, and though (as the restaurant name indicates) they're known for their Prince Edward Mussels, they also serve awesome oysters. Their selection of fresh oysters changes every day, or opt for their shucked-to-order east coast oysters served with spicy aioli. Be sure to order with a side of truffle fries - some of the best in the city.
Flex Mussels, 174 E 82nd Street, (212)717-7772 OR 154 W 13th Street, (212)229-0222
[Photo via @haoig]