I personally like Noah's Ark, it's simply colossal. But make sure you wear sunscreen. There is also a huge indoor water park called Great Wolf Lodge, that place is great, and climate controlled. I heard a month or so ago they were building a nice addition this summer, a sports bar and grill, but i'm not sure when it will be completed. And the Ducks, that is the best reason to go to the Dells, and they've been around for ages. I haven't been on one in a couple years, but they should be around. If your unable to ride a duck or want to try something a little more adventures then take a jet boat tour. The ducks are a classic, but the jet boats are simply amazing.