I second Kodama Sushi. Almost every time I go I see somebody in the theatre business. Joe Allen is great as well. Schnipper's was popular among the Newsies cast, but I'm not sure if many Broadway performers have been spotted there lately.
Green Symphony on 43rd/8th is my favorite. Plenty of B'way people. As well as Juice Generation (Saw Idina, Seth Rudetsky, and Steve Pasquale in the same line).