My husband and I took our three kids (ages 10,10,8) to Ripley's a few days ago when we were visiting the Dells. I had gone before, years ago when I was a kid. I don't think it has changed much since then. It cost our family of five over sixty bucks, and we were through the whole place in about forty minutes--and that includes going back to look at a few rooms.
If you are looking for a "real" museum experience, you might be disappointed here. Most of the items in Ripley's are reproductions. And, of course, you wonder how much of it is fact and how much fiction.
There are few neat exhibits: the shrunken heads, and the part where you can go through a fireplace and up a "secret" set of stairs (we wouldn't have noticed this if another guest hadn't pointed it out). Also, my kids really liked the short swinging bridge you have to walk over. They also loved towards the end, where there are four or five rooms with a (somewhat) hidden button you push, and something happens. We actually ended up going back to a few of the rooms since we didn't realize you could push the buttons until the next to last room (again, another guest had to clue us in).
In short, this is a place that school aged kids, teens, and young adults will probably find fun and interesting. Parents will probably not appreciate the high cost for the short amount of time. Adults may also not like the cheesiness and fakeness of the place. I would not recommend this attraction for kids under the age of 5 or 6, due to the subject matter of a few of the exhibits and because much of the "museum" would possibly bore a toddler/preschooler.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC