Definitely book up for a weekend visit to Emeril's as it is VERY popular (not quite so busy during the week). Their feature Cajun-Creole cuisine is quite superb, IMHO, but, as several have menioned, it is not cheap. It also boasts a great wine list and a cigar bar.
Bongo's is slightly less pricey and more fun in its styling and live music most evenings. The menu is fairly standard Cuban fare (the new Samba Room on W Sand Lake Road does it better, I think) but it is pretty sound and always comes up nice and fresh.
However, like webray, Latin Quarter is well worth considering for its wondreful style, atmosphere and fabulous Latin-influenced food. They pick dishes from all over South and Central America and give it all a really appetising and appealing flavor. Great live music on Fridays and Saturdays, too (although there is a cover charge after 10pm, I think).