A Dells Must do!
Everthing that is the Wisconsin Dells can trace its history back to the river tours that have been going on for 150 years. In that time some smaller operators have come and gone above and below the dam, but the Original (not the other one!) Wisconsin Duck tours have been since they first splashed into the Wisconsin River the only way to tour the Lower River and Lake Delton.
People should remember that these tours are a part of history on many levels. These machines helped the U.S. free the world in WW II. When they came to Wisconsin, they were the first military amphibs to serve in the tourist trade, (before the Ozarks and Tampa and the others)and they have been ferrying people on the centuries old river tour circuits ever since. And as such, they have become living functioning National Historic Landmarks.
So, that respect of history makes them a must do! And they really are fun! Even your teenagers may laugh and smile a bit. Quite an accomplishment from a 60 year old waterlogged jeep.
Now just a word of warning! Because these vehicles were designed to haul dozens of soldiers into combat, they weren't designed for comfort, so if you don't think you will be comfortable in a military transport or feel you need soft bucket seat and air conditioning, a duck ride may not be for you.
Also, people need to be aware of where they purchase their tickets from. If you think you have any questions at all, make sure you buy the tickets at The DuckDock. Those little Kiosks all over the area may be convenient and sell real legitimate tickets, however, many of them are paid on commission, or are operated like the TKTS outlets or Ticketmaster in that they have blocks of tickets they have already paid for and must sell to recoup their losses. Many of these people are knowledgeable and will give you a deal, but just know sometimes its buyer beware. Of course, none of this is the tour operator's fault in the same way its not Metallica's fault for Ticketmaster's $10 surcharge or when Ticketmaster repeatedly overbooks their concerts.
A good, safe place to ask where to get the tickets is usually the front desk of your hotel. The large resorts may have packages for you, and the smaller motels, well the clerk/owner probably knew the tour schedule by the time they were 5. Any lifelong resident does.