I just asked my kids this (they're 16 & 19, 2 boys) to get an unbiased opinion for you and they both said Crystal Palace breakfast at the same time! That was my pick as well, but I didn't want to influence them....too funny that we all picked the same thing!
As for why, I think the Pooh characters really embody the Disney feel at that meal....they all sign the autographs, pose for pictures....the whole bit. They also have a little parade for b-days or whatever. The food is GREAT, there is a ton of it and of every kind you can think of. The staff there has always been outstanding with us and the place is beautiful! We make sure we eat there on every trip....it really is one of our very favorites!