Try the Dallas Children's Museum. Unfortunately its recently moved to the Science building at Fair Park but still in my opinion worth the trip. I think its $4 for kids over 2 and a couple of dollars for the parents. They have at least 10 different pretend play areas for the kids. They can go grocery shopping in a store, put on a puppet show, fly an airplane, work in a dentists office etc etc. and each area is filled with fun clothes to dress in and all the stuff to play the part. Not only fun but educational too.