This is an interesting thread! I had to chuckle because we haven't been yet and I have NO IDEA which is going to be their favorite parks! I have a *hunch* that Animal Kingdom will be my DD's favorite becuase she is such an animal lover (to the extent she has taken her own money to join the Koala Foundation, volunteered at the local animal shelter, etc... and she's only 11!).
It's my 8 year old that should be interesting as he has *always* liked things you wouldn't expect from kids his age. When he was 3, we took him to see SUE at the Field Museum (personally, I find the field museum as a "been there done that" and really don't have much desire to go back anytime) but he LOVED Dinosaurs, DD didn't want to go but I bribed her with "hey look, they have a Gemstone collection" LOL! She was about 5. I honestly thought, we would go there, see SUE & the dinosaur exhibit; then go see the Gemstone exhibit and leave. WRONG!!!! DS was dragging me all over that museum totally entrhalled and thought it was the best thing ever! He dragged me down this nature walk thing that DD refused to even go near because they had kind of scary to her sounds (just critters sounds but...) and I had to read every single fact about everything there. It was *I* dragging him out of the museum telling him they were closing and we HAD to leave!
So, I could easily see him enjoying EPCOT more than MK but you just never know with him, which way he is going to go.
We are going on the Mickey's Magical Milestone Tour and I know it's recommended for ages 10 & up but because of his personality, I am having him come too (any age can go but from finding some info on it, I could easily see why they have the upper age limit my 5 year old would be bored to tears! LOL!)...he will be fascinated because he is always wanting to know more than the average kid about something.