Even though I've haven't been to that many character meals, based on the characters that you want to see, I would say go with Chef Mickey's. We ate dinner there last year and have another ADR for dinner again this year.
If I remember correctly, the characters that we there were Mickey, Minnie, Chip & Dale, Pluto and Goofy, and they were all GREAT!
In looking at my PassPorter, here are some other restaurants that might fit into what you want:
Cape May Cafe (Beach Club)- Goofy, Chip, Dale, Pluto (This looks like it's breakfast only, though.)
Donald's Breakfastosaurus (Animal Kingdom)- Donald, Mickey, Goofy (This one's breakfast only, too.)
The Garden Grill (Epcot)- Mickey, Chip, Dale, Pluto (This one is lunch and dinner.)
Liberty Tree Tavern (Magic Kingdom)- Goofy, Pluto, Minnie (Dinner only)
Hope this helps!