My kids are big Playhouse Disney fans so they really enjoyed the Playhouse Disney Breakfast at H&V (at DHS). They watch Little Einsteins all the time so they had a ball seeing Leo and June.
Every year our "Never Miss" character meal is Donald's Safari Breakfast, formerly Donald's Breakfastsaurus. My two absolutely love it, and the food selection is pretty good...especially the juice!
Speaking of food, I think the best character meal for Dining and Atmosphere would have to be CP. The Puffed French Toast, made to order omelets and pancakes make the buffet a step above the others (for character meals).
Chef Mickey's is good, but since it's the most popular character meal (according to Disney Dining), it's usually always crowded...but if you've never done it, you should probably do it at least once.
I've heard good things about Cape May Breakfast, were trying it ourselves this fall.
So, I recommend Donald's at TH, Playhouse Disney at H&V and Crystal Palace.
Honestly, you can't go wrong with any character meal IMO, they're all pretty good.