Goode Seafood Co and Trulucks are great fine dining seafood joints but a bit pricey. If you really looking for crawfish and crabs, The Boiling Crab seems to be all the rage on the SW side of town with better deal than Raging Cajun IMHO if you don't mind "getting down and dirty" originated out from the West Coast.
http://www.theboilingcrab.com/index.php