Nolita or Soho walk in?
I don't know if you would call Cafe Habana an unknown place but it has great food and can be a real scene. Beware, though, the wait can be brutal. Porcupine was also pretty good the last time I went. Some mixed reviews on Raouls but I have always had a good meal there. They are all in Nolita but unforunately I would not call them "unknown".