I took my four year old niece a couple of years ago. When asked what her favorite things were on the way home I was surprised that none of her top things included a ride. I'm doing this from memory (we went on October 2008) so I probably don't have them in the right order, but here goes:
1. Swimming in the pool.
2. Getting made up like Princess Ariel (Bibbity Bobbity Boutique)
3. Having dinner with Cinderella (1900 Park Fare, Grand Floridian)
4. Trading her pins.
5. Trick or Treating in the Magic Kingdom (Mickey's Not So Scary Halloween Party)
6. Having breakfast with the princess (Akershaus, Norway, Epcot)
7. Meeting Princess Belle (Akershaus, Norway, Epcot)
8. Playing in the playgrounds (Winnie the Pooh, Chip n' Dale, Honey I Shrunk the Kids and the one at the resort). With the construction at MK I'm not sure if the Winnie the Pooh or Chip n' Dale playgrounds are still there.
9. Coloring her mask and getting her charms (Epcot World Showcase)
10. Being in the Lion King show (she was picked out of the audience)
Don't get me wrong, she loved the rides - - and she was quite the daredevil, her favorites were the Test Track, Big Thunder Mountain and Splash Mountain - - but a ride didn't make her top ten. We were there for a week during a slower time of year so we really were able to see/do a lot and I'm a WDW veteran and know how to make good use of a touring plan and fast passes. I don't think we waited in line for more than 5 minutes for anything.
We did do a lot of character meals so we didn't have to wait in line in the parks to see them and could concentrate on the rides. We did Chef Mickey's (Mickey, Minnie, Donald, Pluto & Goofy), 1900 Park Fare for dinner (Cinderella, Prince Charming, the stepmother and the stepsisters), Crystal Palace (Pooh, Tigger, Piglet & Eyeore), Akershaus breakfast (Belle, Sleeping Beauty, Snow White, Jasmine and Mulan - the princesses rotate here so you don't always see the same ones), 1900 Park Fare for breakfast (Mary Poppins, Alice in Wonderland, Mad Hatter, Pooh and Tigger) and O'Hana for breakfast (Lilo, Stitch, Mickey & Pluto). The only character we stood in line for was Ariel, who was a must see for DN. I was hoping we would have her at Akershaus, but she wasn't there that day.
Have a great trip.