A Favorite cheap eats place in New Orleans is Acme Oyster House.  Yes it is touristy but the good & cheap food along with the experience is what makes it.  If you're lucky, you may snag a spot at the oyster bar. If you're not a seafood eater get the smoked sausage po-boy with a side of fries. The red bean poopa (red beans and rice in a bread bowl w/ sausage links) is a favorite.  You can also try a fried oyster po-boy with no bread.  Strange huh? ..but a waiter's inside scoop is that you get more that way then ordering the platter.   Wait staff is always very nice and attentive.
 
Another great cheap eats place is Johnny Po-Boys.  Po-boys are served ala carte and there are dozens to pick from.   The place is teeny tiny so be early or late when you go or you won’t find a table.   The Johnny’s special was yummy (Roast beef and ham) and the gumbo was good too with a half a crab sticking out of it.
 
A third cheap eats place is the Napoleon House. The menu was limited due to the short staff from Katrina.  Try the mufflatta and the jambalaya.  Both were very good and cheap.   The restaurant is intimate and wait staff was nice.

If you need a break from cajun food and are looking for a great hamburger, head to  Port of Call on Esplanade Avenue, just on the outskirts of the French Quarter. The wait may be long but get a fruity concoction from the nautical bar to pass the time. Or head to Fiorella's on Decatur, right outside the French Market for some fantastic fried chicken. The chicken is cooked to order so there is a bit of a wait, but the food is well worth it, steaming hot and super juicy! A few doors down from Fiorella's is the Louisiana Pizza Kitchen, a brick oven pizza place with many styles of pizza to choose from, delicious and it won't put a huge dent in your budget.

If you venture outside of the French Quarter, try the barbeque shrimp po-boy at Liuzza's by the Track, called such because it just a short stagger from the New Orleans Fairgrounds and Racetrack - site of the annual Jazz and Heritage Festival. This is the pre-Jazzfest warm-up spot, so if you're feeling festive have a bloody mary or an Abita beer in a frozen scooner.

If you're uptown looking for some great bar food, try Cooter Brown's at the corner of St. Charles and Carrollton Avenues. You can order fresh shucked oysters (only in months with an "r") at the bar and also a variety of sandwiches (even alligator) with cheesy tots! Check out the great artwork on the walls which puts a little personality to every different beer bottle they have (which is a lot!).