If your family is like mine, we dance. A lot. One of the best times we have is using Just Dance on our Wii. Unfortunately, a Wii is expensive and so are the games.
We have discovered that you don't need to have that expensive piece of equipment to be able to rock out and shake on down like the professionals in music videos. Many of the dances on Just Dance have been added to YouTube. This is one of our favorites. Using YouTube instead of the Wii also helps to eliminate any upset or fighting related to the number of players, who has which controller, and who has the most points. Most of the videos are done by very high scoring people, so it is cute to see the kids getting an ego boost about their "high scores" that are embedded into the video.
If you do have a Wii and want to try out the game, check to see if your local library has video games for check out. Our local library has a decently large and up to date collection of games.