I recently went through several Dallas Cajun/Creole restaurants, tasting etouffees. Here's a summary of the results, with more details and photos at the link below.
Alligator Cafe. I was interested in trying this place after positive word on Charles Kemp's East Dallas Restaurants web page. (DMN was also high on it.) The crawfish etouffee was unusually tomatoey, with an appropriate heat level and an aftertaste of brown roux. The crawfish (frozen) came out rubbery. Not the most traditional preparation or the best execution, but a reasonable value at $8 (lunch or dinner).
Nate's. No lunch portion was available, so I ordered a combo of etouffee and fried tails off the dinner menu. The fried crawfish had an off taste (possible freezer burn). That taste wasn't noticeable in the etouffee, largely because the seasoning was so overwhelming. Onion and cayenne were so pronounced that it was hard to taste anything else. Imbalanced and unpleasant. Texturally, it looked like it had been thickened by pureeing, rather than by cooking it down (or using roux). One of the pricier versions I tasted (+/- $16), but among the worst.
Dodie's. This etouffee was similar in character to Nate's, in that onion and hot pepper overwhelmed all other flavors. This was the most watery etouffee sampled. The tails were cooked just right. Not as bad as Nate's--and, at $8 ($10 for dinner), it was much cheaper--but it reminded me of why I rarely bother with Cajun outside of Louisiana.
Pappadeaux. The dominant flavor here was brown roux--so much so that it tasted more like a gumbo than an etouffee. It placed in the middle of the pack, not because of its virtues, but because of the vices (e.g., gross imbalance of flavor) of the poorer performers. Not a bad dish, but not one I'd order again. This was the most expensive etouffee tasted.
Vermilion. I didn't expect to find a great etouffee in Dallas, but here it is (pictured below). The traditional components of etouffee--onion, celery, and bell pepper--are combined in perfect proportions, so no one overwhelms the others. Heat is at an appropriate level (i.e., subdued). Tails were tender. Excellent flavor, overall. The chefs, alumni of Prejean's in Lafayette, LA, know their stuff.
Of the etouffees I sampled, only Vermilion's was a genuine pleasure to eat.