I dont have the Zumba for the Wii, but I do have the DVD Exhilarate set and I absolutely love it!!! The music is great, and the work outs are so much fun!!! Here is a link to the DVD set I bough, it is a little pricey but in my opinion worth every penny!! I can work out and actually have fun doing it!!
https://www.zumba.com/shop/product/zumba-exhilarate-dvd-experience/
I have seen the "Just Dance" set for the Wii because my nieces and nephews got it as a christmas gift and were visiting me at my house and it looked like alot of fun, they all loved it and I thought it looked like fun when I was watching them all doing it!!
I am thinking the Zumba is probably better for more of a "workout" though, and maybe the Just Dance is more for fun??? but I guess either way it is good if it motivates you to get up and move!!