Narcoossee's is a 2 credit meal.
For one-credit, special, for a non-park meal, it depends what you're into.
Ohana (Polynesian) is a 1-credit, and very festive, but it's not elegant.
The Wave (Contemporary) is an underrated gem.
Raglan Road (Disney Springs) is fun, and has entertainment.
Captain's Grille, at the Yacht Club, may be a best bet for a 1-credit, OOP, elegant steakhouse, though, if you have thoughts of a quieter place with steak. Like every non-signature, it's "casual" dining, but the menu is pure classic steakhouse.