Stinky's if you're looking for fun and it's my favorite food. D&K also has great food and if you're looking for a little more atmosphere (but in no way fancy/stuffy)-we ate in a smaller offshoot room on the side that they would probably let you have to yourselves if there's not a big crowd. People are raving about George's at Alys beach but we didn't make it there last trip.
You could always get a dinner to go and have a beach picnic if it's not windy, I can't think of a better sunset dining view!