Hello...we stayed at Pop Century with 2 little kids on this vacation and we were CROWDED. After 4 nights we moved about a mile up the road to Holiday Inn Family Suites (barely off Disney property) and it was wonderful. I'm sure you probably want to stay on property, but this particular hotel was perfect for our family. The kids loved having their own room with bunk beds and all that, and in the bunk bed room there is a 3rd bed that folds out of the wall, so that room can actually sleep 3. Also, we were able to park right next to our room, which was helpful with 2 little kids and diaper bags and all kinds of stuff to lug around. While we stayed the 4 nights at Pop Century it was SUCH a pain to have to walk so far back and forth to the car. Plus there's a free breakfast buffet each morning!
You should check it out. I found it to be a perfect resort for parents with young children. And the proximity to Disney was wonderful (the entrance sign for Disney was seriously RIGHT by the hotel). Here's a link:
http://www.hifamilysuites.com/indextourb.html