There's a team for that! You should check them out!
I have used the Wii Fit for fitness in the past. Once I was able to do the Wii Fit exercises easily, I had to do something else in order to spend my exercise time efficiently, though. I also used the EA Sports Active game. I still enjoy doing using it for amusement & sometimes tracking, but I'm now too fit for it to count as exercise.
It's definitely a fun way to get yourself moving, but you will probably grow out of it more quickly the closer you are to being already fit. It took me a few months, but I was pretty bad off at the start.
My Sparkpage is set to private, but I'm open to SparkMail!
"People often say that motivation doesn't last. Well, neither does bathing--that's why we recommend it daily." - Zig Ziglar