Testers assessed the workout the games provide, using a monitor to measure heart rate. It turns out all the games aren't equally effective. Some are a lot more strenuous and provide a real fitness challenge, whereas some of them are more just party games and really don't provide a great workout.
Nike Plus Kinect Training and Your Shape will give you tougher workouts, while Just Dance 4 is less grueling.
The gaming console you use can also make a difference in how much of a workout you get. Consumer Reports says that the Xbox is going to the most effective for these types of games, because using the Kinect, the camera can actually track your full body's movements, whereas with the Wii U or the Playstation 3, it can only see the controller, not your full body. So it's easier to cheat the system, and it's not tracking your body as accurately.
If you're looking for a game that can give you a tough workout, Consumer Reports recommends trying Nike Plus Kinect Training.
For a good cardio workout that also provides some fun, Consumer Reports recommends Zumba Core. The quick dance steps get your heart rate up -- and keep it interesting.
Zumba Core is available for Xbox Kinect, which does the best job of making sure you get a good workout. But if you have a Wii U or Sony Playstation, it's available for those, too. Just make sure you don't game the system, or you might as well stay on the couch and play Mario Brothers.