Depends on who you want to see.........Minnie's will have your classic characters like Minnie, Chip, Dale, Capt Hook, Max, etc and also the Winnie the Pooh characters like Pooh, Tigger, Eeyore. They offer a decent sized buffet with the normal choices.
Goofy's Kitchen offers a very large buffet. You will see 4-5 (average) characters from Goofy, Pluto, Mickey, Chip, Dale, a Princess or Alice, etc.
Storyteller's offers more of the animal variety: Chip, Dale, Meeko, Kenai, Koda, Brer Fox, etc. You can order off the menu or do the buffet. (the prices will be equivalent since you are paying for the experience)
Surf's Up with Mickey is my new favorite. It's a smaller buffet but they offer different things not found at the other buffets. This is the only meal you can see Mickey and Stitch at. You'll usually see 2 or 3 more like Pluto, Goofy, Minnie, or Daisy.
Hope that helps!!