I used fit plus for the a few months to get me in the habit of working out but around the first of January I got the biggest loser challenge game for the wii and have lost 12 lbs since then! It's a great workout
I love my Wii Fit, I have plus, and did have the Biggest Loser game for a while; I also have the Zumba game. All of which have helped but it's just something to break of the routine of the gym.
It never actually helped me lose weight. But while I lived with my sister I had to get up around 6am, get to the bus stop by 7 (5min walk), sat in school all day. Bus showed up around 315-4pm so never knew if there was enough time to go for a walk, then got a 5min walk as long as it wasn't raining. if it was the driver dropped me off at the door. Then since I normally had to babysit, I couldn't go for a walk then because the oldest would never listen to me. I gained 25-30lbs in the first 3 or 4 months of being there. Then she got the wii and I started getting up earlier 3 or 4 days a week to squeeze in half an hour on the wii then 3 or 4 days I'd try and squeeze in another half hour before bed. I managed not to gain any more weight the last 4 or 5 months being there.
and right now the wii fit is pretty much the only exercise I'm getting (and ddr but I do the choreographed version so don't really work up a sweat...I normally just use it to warm up a bit) and with trying to eat less/healthier I lost almost 6lbs in 3 weeks...
I'm not sure how well it aids weight loss as I've always used it along side other methods. I can say that it can help with your muscle tone and core stability, especially if you use the yoga and muscle development sections correctly - some of those workouts are quite hard!
I also found the boxercise was quiet effective as well as gentle exercise, if you unlock the full time