DD has been at age 2, 4, 7 , 9 and 10y and has loved all he parks each time. But we are pretty much on the go all the time and we do parks every day - either Disney, Universal, Space Centre, Water parks and in the past SeaWorld. Sometimes we have a day at the beach.
We have stayed in villas mostly but once in a Disney hotel. Hotel was fine and it is very easy to drive in and out and go elsewhere. Not an issue at all, no more so than staying in a villa tbh.
The Disney parks:
Magic Kingdom - the one for the little ones especially and for the "magic". Plenty f rides, a few show, lots of parades, fireworks, light show. Can see lots of characters here too.
Animal Kingdom - a quieter, less rushed day but often more humid and hot due to the planting. Less rides here. Great Lion King show. You can see plenty of animals on the safari and also on the walk through animal places in Africa and Asia. And you can do the train to Rafiki's island place where you can see characters and there is a petting farm. Has a parade in middle of day.
Epcot - another quiet day but lots of walking. A few rides at the first part and some hands on exhibit, etc. The Nemo ride leads into the aquarium. There is a ride where you sit on a moving train type thing and meet dinosaurs. Then there is the World showcase with lots of countries represented. This is mainly walking round, a few cinema things where countries show short films, a couple of gentle rides. There is also a Phineus and Ferb spy type game children can join up and play. No parade. Light and firework show around the lake at night.
Hollywood Studios - based on films. A fair few rides, amazing Beauty and the Beast show. Parade. Excellent car stunt show. Meet some characters. Some other shows like the Muppets.