Hi there. I didn't officially cast a vote because I've only been for dinner and it was not good, so I would vote for Breakfast!
The food was actually really great for dinner, but it was total mayhem in there, the characters were skipping tables, there was someone we never saw (now I can't even remember who), etc. I think each character was stopping for a picture with each table and they were leaving before signing my girls books. Not a pleasant character interaction especially considering all of the awesome character meals we had. Looks like breakfast might be a safer bet.
As for hanging out with Pooh and Tigger - we went to the toy store at WS and they were spending 5-10 minutes with each family. Playing games (rolling around on the floor with my girls) and taking pictures, etc. It was a nice interaction. Try that too!
Have fun!
Lesley