I've owned Wii Fit for a week now. My initial startup age was 33, which I didn't think was that bad. Tonight was the first time I dove into all the categories of the game, other than just the balance games - which for me are the most fun.
I focused on a lot of the strength exercises, and quickly realized how out of shape I was. The push-up side plank exercise is going to leave me sore at work tomorrow for sure. It was pretty interesting doing a push-up on the wii fit board, but surprisingly worked pretty well. The side plank part of the push-up is what I'm going to feel tomorrow.
The other exercise that's going to leave me sore was the leg lunges, I haven't gotten that good of a leg work-out since I was in track in high-school. I like how it counts your reps for you, which really makes it so you can't cheat out of that last rep, not matter how much you want to.
I really think that if you are someone who doesn't like going to the gym, but still wants to work out, that the Wii Fit is definitely something you should try. It really works a lot of different core muscle groups, from Abs, to legs, to arms, all within one work out, and the game comes with your own personal trainer.