Best affordable N.O.???
If you are staying in the Quarter or CBD venture to Mid-City on the Canal Street bus. Old standbys like Liuzza's or Mandina's, blocks from each other, will do you fine. Casual dress and plenty of choices. Please bear in mind that the difference between a lunch at Liuzza's and one of the better restaurants in town will probably only be $10. Lunch is a great bargain no matter where you go. $25 can have you eating like a king.
If you do take the bus do stay on a local Canal bus, avoiding those that have "Express" in their title.
re: Mark T.
Mandina's is a great place, but if you go for dinner, get there early or plan to wait, with lots of other folks crammed in the bar or out in the heat, drinking a beer. I second the Liuzza's as well. Can get really busy there too. If you go in the cooler months,do try the hot tamale's at Liuzza's, they're sort of italian style and wonderful.