I have taken my wife and four kids to Disney World on three different occasions, each stay being about two weeks long. Each time we went, we decided to split up our time among two different resort types, one week at each. So far, the most kid friendly resort was the Polynesian Resort. Hands down.
First of all, the pool is awesome. Probably the best one in Disney, complete with a volcano with a slide that goes through it and a huge waterfall that the kids can play under and around. There is also a club for the kids called Peter's Pans that is incredible. It has every thing a kid could ever want to play with there, including a full size movie screen that constantly shows Disney movie's. There is art, dressup and all kinds of awesome things for the kids to do. They even feed them while they are there.
As for me and my wife, we most enjoyed the Bistro there at the hotel which has the best menu and food. The grounds were incredibly beautiful. We also rented the little boats at the marina and also took an evening cruise on a pontoon boat during the fireworks which was a once in a lifetime experience - amazing. We took the aqua taxi to the other hotels to check out their restaurants and bars, but usually found ourselves migrating back to this resort for it's laid back style.
The room was nice and comfortable and all of the staff was incredibly sweet and wonderful. My oldest daughter received balloons and a signed picture of Mickey and Minnie on her birthday so she was thrilled. The whole family rode the monorail every night during the fireworks (except for the night the wife and I rented the pontoon boats) to get a birdseye view and it was awesome.
But no matter which resort you pick, nothing compares to the joy and excitement of watching the look of magic in your kids faces. To see the look of utter surprise and wonder is worth the entire cost of the trip. And I guarantee you, it's those moments that you'll treasure for the rest of your life.