I went twice recently to Bistro Cassis (14th street btwn 7th and 8th) for brunch. They have really nailed the salade frisee aux lardons. Perfectly cooked bacon and dressing. It's the most authentic version I've seen in NYC.
Also good and unusual on their menu is ouefs meurette (Eggs in a red wine sauce).
The service was a bit disjointed, the coffee was lukewarm, and my primary complaint is the lousy and loud music they play, but otherwise I think this place is a winner.
oh, and someone recently was asking about moules/frites. It's on the menu here but I have not tried it.