The Wii Fit Plus - this is the model I got for Christmas. The balance board is really easy to use. I do have another game that uses it but I haven't tried it out yet- just been using the wii fit program.
When you first set it up you have to give it info about yourself like your birthdate and hieght. It is set up for you to check in everyday- but you don't have too- I have done it everyday since I started and I am going to measure my dogs once a week- they only get a pound amount- but DH has only done it once.
The daily test starts by asking you if you have light or heavy clothes on and then you step on the board and it measures your weight/bmi and balance. After it is finished it will tell you your bmi and weight- you can choose to have this information password protected so no one else can see it but I haven't bothered to do so 9no one in my house would do anything with it). Then there is another short test of mental/balnace stuff- it has been different almost every time I have tested. You stamp the calendar each day when you take the test and the little figure is positive as it talks with you- it will ask about my eating breakfast, remind me to drink water, ask about my taking breaks, praise me for coming each day, remind me that we have different weights throughout the day.
On the first day you set up a goal- my goal is 5 pounds in 4 weeks so it tells me how I am doing on that goal and how much further I have to get there.
There are balance, strength, yoga, and aerobic activities, along with some games. As you do each activity it has a timer that shows how long you have exercised and it counts the calories for the activity. You can rotate through info on the counter for total time, time today, and calories today.
There is a chart section that monitors your progress. You can add steps and other asctivities that you do into this and it adds to the amount of activity done on the chart- you can see the kinds of activities you have done (grouped by type) and apromximately how long you have spent on them. It will also show you what food you can eat that would be the same as the calories you have burned off.
There is also a training program that puts together a string of activities for you to do to target something specific- I have tried the one for overindulged, shoulders & back, relax. Each one takes about 6-10 minutes and has a variety of things to do in it.
I wouldn't say any of the workouts are that hard but it is a good something for days I don't have zumba and the strength items while not burning calories are helping me with balance and will eventually (I have only used it 4 days) strengthen my muscles. I like the charting it is doing for me.
That is what I can think of- if you have any specific questions feel free to ask and I will try to answer them.
hope you make it through the day
and taking the Christmas decorations down. 
