I have not been to the Wilderness.
Great Wolf Lodge is my favorite. Has great things for the whole family, plus if you have younger kids there is a story time every night that my daughter loved. Have gone in both the summer and winter, loved it all season!
Kalahari is a lot of fun but I would say that is geared towards kids 8 (may be 10) and older. I did not go with my daughter, went with a group of friends and to me there would not be as much to do if under 5.
Chula Vista... we disliked. Now we went in the winter so did not use the outside water part. The inside was cold, the kids play area water was the coldest and we complained and all we got back was "deal with it, it is winter, it is cold" so they will always get bad reviews from me.
I know there is less to do after Aug/Sept in the Dells, places do close down BUT if you go to a resort/family place there are many options as things to do and food to eat. Also if you get a place with a kitchen in it you can save tons of money by making your own meals and eating out only once.