In the french quarter, you have the option of some 'touristy' type restaurants with cheap fried seafood and beer mixed in with some really old classic restaurants.  If you want to stay in the french quarter and try a casual less pricey decent lunch, i'd consider Acme Oyster House NOLA Restaurant Antoine's Restaurant .  For a little higher end experience Tableau The Pelican Club Napoleon House Original Pierre Maspero's are good options.  If you are willing to take the street car or walk Cochon
Emeril's Delmonico Commander's Palace Restaurant are very good options but can be pricey.  Also be sure to stop by Café Beignet or Café du Monde for dessert and famous chicory coffee.

Good morning!  My recommendations are kind of off the cuff, but waking up, reading this question, I went with five (make that six) places that I would go to for lunch if I was leaving today.  The recommendations are as eclectic as the city itself.  In no particular order,  Willie Mae's Scotch House, Cochon Restaurant, Juan's Flying Burrito, Commander's Palace Restaurant, and Acme Oyster House.  Oh, and if you like Vietnamese food, the West Bank has a little Vietnamese community and one of the best bowls of Pho, I have ever had at Pho Tau Bay Restaurant.  Enjoy safe travels!

Commander's Palace Restaurant is as old NOLA as it gets.  Take the St. Charles street car out and back to complete the experience.  An informal lunch at Stanley for a big bowl of gumbo will also do the trick.

These two restaurants are the most famous for their lunch atmospheres:

Commander's Palace Restaurant

Galatoire's (particularly Friday)

Hands down.

oh geez, i highly recommend Commander's Palace Restaurant, you can read a review of it here :)

http://coffeechalk.wordpress.com/2014/06/30/nola-trip/

My personal favorite is K-Paul's Louisiana Kitchen, but they have a very abbreviated menu for lunch...but great though.

Like others have said, Galatoire's and Commander's Palace Restaurant are famous for lunch but both will be a bit more pricey then K-Paul's.

For an old soda fountain feel, head over to The Camellia Grill and get the chili cheese omelet with fries.

For the best fried chicken (some say in the world), go to Willie Mae's Scotch House be warned it is in a not so nice area of town.

If you want "Old New Orleans" feel for lunch, Galatoire's is the ONLY answer