You picked the worst week to go (between Christmas & New Years). Everyday will be packed since schools are out, but I would say historically Wed or Thurs will be the least crowded.
I've eaten at every character meal in the
Disneyland Resorts
(except for Breakfast w/Minnie @ Paradise Pier).
Breakfast @ Storytellers Cafe (Grand Californian-only do characters during breakfast) had the best tasting & best variety of breakfast out of them all & the atmosphere is warm & beautiful, but character interaction was little. Chip, Dale, Pluto & Donald remain at the entrance for greetings & do not come around to the tables (which I thought was great, because it gave my kids a chance to eat). The kids can go over to them whenever the want. And every 30 minutes or so, the characters to "follow the leader" with the characters around the restaurant.
Breakfast @ Plaza Inn (Inside Disneyland park-characters only during breakfast). Normal breakfast fare w/ Pooh, Tigger, Eeyore & Piglet(only place in the park to see Piglet). Very good Character interaction & BEAUTIFUL Victorian style restaurant.
Lunch & Dinner @ Avalon Cove (Disney California Adventures). Lunch & Dinner have similar menus, but dinner price is actually pretty reasonable ($17.99 includes rolls, soup or salad, entree w/side, drink & dessert). The food is really good as far as theme park standards go & the character interaction is great: Ariel, Sailor Minnie, Goofy, Chip, Dale & Pluto. This is my favorite Character meal of all. The restaraunt is decorated in "Under the Sea" motif, the characters actually play & joke around with the kids & it's an actual sit-down meal (not buffet).
Breakfast & Dinner @ Goofy's Kitchen (Disneyland Hotel). The food for both meals has a huge variety. The character interaction here depends on how crowded it gets. When we went during dinner it wasn't & the characters literally stayed at our table. Baloo fed my daughter, The Mad Hatter came to tell us jokes w/Alice, Pluto was licking everyone...etc. The characters here vary the most compared to the other restaurants, But Goofy is always there. P.S. Dinner here is about $10/per person more than Avalon Cove!!
Hope this is informative and if you have any other questions, Please ask!!