Not sure exactly what you are looking for, but I copied most of this from allears.net and edited what I knew to be incorrect. (Some of the info was really outdated.) I am not 100% sure about the info on CRT, or Playhouse Disney meals are since I have never been to those two. I'm sure someone will correct me if I have missed something. The only meals that I did not include are the ones at the Swan/Dolphin.
If you are looking for Ariel, she is sometimes at Princess Storybook Dining in Norway. (and of course her grotto in the MK) Hope this helps you.
Magic Kingdom
Crystal Palace - This restaurant serves three meals per day with Pooh, Tigger, Eeyore and Piglet. Meals are served buffet-style.
Cinderella's Royal Table - Located on the second floor of Cinderella Castle this restaurant serves the Once Upon A Breakfast character breakfast every morning.
-- Breakfast and Lunch are Disney Princess-themed character meals. When you arrive at Cinderella Castle for your reservation, a photographer will be on hand to take pictures of your group in the lobby, before you are seated in the dining room. Photos must be purchased.
-- Dinner is a fixed-price, set meal, also, hosted by the Fairy Godmother, who will lead the observance of special occasions like birthdays and anniversaries. You will also have the chance to have your photo taken before dining, with a photo package offered to you during the meal.
NOTE: Payment in full with a credit card will be required at the time of booking for all meals at Cinderella's Royal Table.
Magic Your Way Plus Dining Plan will be accepted at Cinderella's Royal Table meals, requiring TWO table service credits.
Epcot
The Garden Grill - Chip and Dale's Harvest Feast - Located in the Land Pavilion in the Future World section of Epcot this restaurant features dinner with Mickey, Chip and Dale, and Pluto, all attired "farmer-style".
Princess Storybook Dining - All meals have five princesses. A family style American breakfast is served at the Akershus Royal Banquet Hall in the Norway Pavilion at Epcot. Lunch and Dinner are Norwegian style dining. A cold buffet to start with your main entree ordered off a menu. Included with your meal is a photo package.
Disney's Hollywood Studios
"Playhouse Disney's Play 'N Dine at Hollywood & Vine" with Jo Jo and Goliath from "Jo Jo's Circus" and June and Leo from "The Little Einsteins". Breakfast and lunch feature the characters singing and dancing to favorite Playhouse Disney songs.
Tusker House - The Animal Kingdom features a character breakfast, called Donald's Safari Breakfast located at the Tusker House in Africa. Characters include Donald, Daisy, Goofy, Mickey.
RESORTS
Cape May Cafe - Beach Club Buffet breakfast is served here every morning. Goofy, Pluto, Donald are on hand and the meal is served buffet-style.
Chef Mickey's - Contemporary Resort - Chef Mickey's serves breakfast and dinner buffets with Mickey, Minnie, Donald, Goofy, and Pluto.
1900 Park Fare - Grand Floridian
Breakfast - Supercalifragilistic Breakfast buffet with a variety of characters. Currently there are Mary Poppins, Alice in Wonderland, and the Mad Hatter and Pooh character.
Dinner - Cinderella's Gala Feast - Dinner buffet with Cinderella and Prince Charming, the step-sisters and step-mother.
Polynesian -- 'Ohana Character Breakfast - every morning. Characters include Lilo and Stitch, Pluto and Mickey. The meal is served family-style.