Hi, Elaine!
One of my favorite buffets is
Cape May Café at Disney's Beach Club Resort. Start with the salad bar and clam chowder, move onto a meat carving station, then hit the wonderful seafood buffet with crab legs, clams, and more. And I promise, you will not be visited by any costumed characters while enjoying your meal!
If you are feeling a bit more adventurous, try
Boma at Animal Kingdom Lodge. This buffets features a wide range of entrees and sides, all with an African flare. No characters here, either.
Enjoy a night of great food, wonderful company with your Prince Charming, and NO character interaction. Have fun!
Cathy