Ooh, I forgot....Zydeco Kitchen in Pearland!!!!!! They also own the one downtown you are talking about.
There's alsoa Babins in Northwest Houston across from Willowbrook mall. I can honestly say that I could NEVER get tired of Pappadeaux's. This food is great. Me and my wife order a bottle of wine with our meal. We love it.
goode company seafood, off kirby, while not strictly cajun, is very good. also denis seafood on westheimer and dairy ashford is underrated.
If you love Pappadeaux, then you won't like Babin's unless you are looking for a larger selection of fresh fish. For the purely cajun food, Babin's is not near as good as Pappadeaux's. Whenever I get dragged there by coworkers and I get something, I'm always thinking "why didn't we just go down the street to Pappadeaux's, its twice as good for the same price." If you are in the Willowbrook area, there is a place called Beaudreaux's right across 249. They are somewhat decent if not a little overpriced. I agree that Treebeards is awesome, especially on Travis. Red beans and rice all the way...the sausage is awesome, all the French bread you can eat...plus an iced tea for less than $6. (the price you get for jury duty since its right near the courthouse.)
My wife and I tried the gumbo there at lunch one day last week, specifically because I remember you recommending it in a thread a while back. I must say you were right, that is some damn good gumbo! And at lunch you can get a bowl of gumbo and a salad for $7.99, heck of a deal. I used to love eating Muffaletas at the Treebeards in the tunnels downtown. I was there last year though and was dissapointed to find out they've stopped serving them, at least at that location.
Two Places that haven't been mentioned yet, that are pretty damn good: New Orlean's Po Boy on Main St. Boudreaux's Kitchen on the West Loop Feeder. Both pretty inexpensive for Cajun, as well. I have got to try Denis'. Only good cajun place I haven't tried.
Do the Seafood Gumbo at Treebeards in the Church. Only available on Thursday/Friday, but it is the best gumbo for $6 you've ever had.
Really? The Houston Press claimed otherwise, saying it was the last authentic Cajun restaurant in town. http://www.houstonpress.com/issues/2004-09-30/dining/cafe.html
There's also a place called Rockfish Seafood on FM 1960 that was pretty good. They server cajun dishes, but may not be considered a cajun restaurant.
None of these are inexpensive (though they're all tasty): Babin's, Pappadeaux, Floyds (aka Mardis Gras Grill), Ragin' Cajun, and Denis' Treebeards is tasty and inexpensive. I haven't tried Cajun Town yet, but they get a good review from the Houston Press and seem to be affordable. -- droxford