We went to Hollywood & Vine for a late breakfast last October, when DD was 2 1/2. Characters were JoJo & Goliath and two of the Little Einsteins (June and Leo). We got lots of table time with all of them, except for Leo (but we did catch him for a siggy on our way out). Every 15 or 20 minutes they invite everyone to get out of their seats and join the characters in the middle of the restaurant for a quick little dance party. DD loved it, and actually I think my ILs who didn't even know the Playhouse Disney characters loved it the most.
At almost-3, DD also really loved our lunch at the Coral Reef restaurant. We were seated right up at the glass, and DD would squeal with delight every time a shark swam past.
Last trip we were with two other kids who were afraid of characters so we stayed away from character meals - next trip we're hitting the Norway Dinner and Crystal Palace breakfast, plus we're going back to Coral Reef.