While I've only tried two (and have two planned this time brkfst at CP and dinner at 1900 PF). I liked CM brkst for the whole "disney" feel and Donald's brkfst for the food. I voted for CM as my favorite though.
1900 is my fave breakfast, character or not. I think the food is great, lots of variety, good value, and good service. Having some great "classic" characters there is just the icing on the cake! =)