Bon Ton on Magazine near Poydras is classic also Mandina's on Canal. Those are 2 classic neighborhood restaurants.
I love Cochon on Tchop St. It may be pushing the definition of "casual" but K-Paul is delicious. Dante's Kitchen over near Tulane Oyster House on Royal
For the life of me I cannot understand how someone would ever entertain the thought of eating one of those God forsaken things. I couldn't even begin to imagine the strains of bacteria that are being grown in those pans of hotdog water.
I have been eating lately at a place called the Pelican Club. 615 Bienvielle 312 Exchange Alley (Near the parking garage at Hotel Monteleone) Not crowded, good drinks and good food. It has been there for a while but i just discovered it. www.pelicanclub.com
I like the the Gumbo Shoppe in the quarter. Very laid back not knock your socks off great, but good. I go there pretty frequently