would you go to picholine, bar boulud or nougatine before the opera?
Trying to decide among those three is difficult because all are, imo, excellent. All are French (my favorite cuisine), but each has a different style.
Picholine leans Mediterranean, has one of the best -- if not *the* best -- cheese programs in the city, is the most formal (most men wear jackets, though they are not required), and while there are moderate ways to dine there, it is the most expensive of the three.
Nougatine is casual but with a touch of elegance, and Chef Jean-Georges Vongerichten incorporates Asian influences in many of the dishes as he does in the formal dining room.
Bar Boulud is the most casual of the three. It is crowded and bustling. The charcuterie is its strong suit, but the rest of the menu is not too shabby.
Picholine is certainly French inspired, but Mediterranean only in the name. Before the opera you will not have time for the cheese course unless it is your dessert. Don't miss the sea urchin panna cotta. If you are going to the opera, you should be well dressed, although not everyone is unfortunately.
I agree with RGR's description of Bar Boulud. We go there before a Saturday matinee opera.
You should add Telepan to your list.
It always depends on your budget...the prix fixe is a bit steep for my high school teacher's budget so I love having dinner there at the bar. Is it less expensive but you still get to enjoy the experience. I had the best white gazpacho there this summer. I even went twice on the same vacation since I had enjoyed it so much! Eric, the bartender, is very knowledgeable about wines and food and always chats a bit with you. He takes care of the patrons at the bar. I often have 2 appetizers plus the cheese plate when I go there.