I love the Frying Pan, because it's so unusual for New York City. Situated next to Chelsea Piers, this bar is on a pier next to an old boat and is a great place to enjoy outdoor dining, drinking and music right on the Hudson River. In spite of the multi-million dollar complex that is Chelsea Piers, there is no pretension about this place. Just park yourself at one of their tables, pop open a beer, and relax while watching the boats going by on the Hudson. They also have an outdoor barbeque and while it's nothing special, it lends to the casual and relaxed atmosphere and makes for a good nosh.
Check ahead though, because it's also very popular for private events which are closed to the public. Their public events, however, are great fun, and in the summer there's usually a weekly dance party for after work.