Sugartown posts one of my favorite peformances: Blossom Dearie singing "Manhattan." All you Manhattanites (you know who you are!) need to download this one. It's not really the city you know today, but the city you wish you knew today, with a line as delicious as "the subway charms us so / when balmy breezes blow / to and fro."
Her version, slow but not melancholy, I would agree with Sugartown, is probably the definitive. Get it fast!