I agree with others--go for one of the latest seatings at Minnie and Friends for breakfast. That's what we did two years ago and what we'll likely do again this September.
We had one of the last two breakfast seatings there and, according to my records, prior to the meal we rode on Dumbo (twice), Teacups, Buzz Lightyear, Astro Orbitor, and the Canal Boats. Stopping to eat after doing those rides was perfect as my children were ready for a break.
We saw Minnie, Tigger, Pooh, Fairy Godmother, Captain Hook, Chip, and Dale.
Edited to add: If one of the characters is scary to your three year old, the characters are REALLY good about going away as soon as you (or they) realize they're causing a problem. My 2.5 year old did NOT like Captain Hook--as soon as we all realized this, Captain Hook vanished from our table and the Fairy Godmother quickly came over to console him. It was wonderful!