This should probably be posted (and might get moved over for you by a mod) on the Disneyland side. But since I am DL regular I can go ahead and give you some information:
Grand Californian: Storytellers Cafe. Usually you will see Koda and Kenai from Brother Bear as well as Chip and Dale. Meeko also appears sometimes. It is a buffet with characters but only at breakfast. Lunch and dinner, still a buffet but no characters. They also have a standard menu you can order off of if you don't like buffets.
Goofy's Kitchen at the Disneyland Hotel: Goofy, Pluto, and usually Minnie. Also, you will usually see Chip and Dale. In addition you will see a few other characters including a princess or two. We have seen Mad Hatter, Peter Pan, Aladdin, Genie, Captain Hook, Alice, Baloo, Wendy and a few others through the years. It always has a wide varitey of the characters who dance and play with the kids. It is a buffet and has characters for all three meals.
Minnie and Friends at the Plaza Inn inside Disneyland. This restaurant features characters at breakfast only. MInnie is there and usually some Pooh characters as well as a few others. Fairy Godmother is there quite often. It is a buffet and since its inside the park requires park admission.
Ariel's Grotto inside DCA: This is a fixed price non buffet meal, with princesses, and lots of them. The princesses rotate thorugh the restaurant and visit each table. It is lunch and dinner only and since its also inside DCA requires park admission.
Lilo and Stitch Breakfast at the Paradise Pier Hotel: This one is a breakfast buffet with Lilo and Stitch and generally Pluto, Minnie and sometimes Goofy. They are all dressed in Hawaiin get ups, do Hoola contests and other games with the kids. Its in the PCH Grille restaurant but the characters are only there for breakfast. You can also order of a standard menu if the buffet does not interest you.
Note that all three of the onsite hotels are within easy walking distance to each other and the two parks. They are all fun and the food has been good at all of them when we have eaten there. So just pick the one that has the characters you want to see! Have fun at Disneyland!