I only work out at home as well. For me, it's not so much the idea of people seeing me, as it is being motivated to actually go somewhere to exercise. I converted my basement to a nice little work out area so there are no excuses. I can workout in my PJ's if I choose to do so

I use workout videos as my main source of exercise. My videos of choice are walk at home videos by Leslie Sansone. It combines power walking with simple kicks and leg lifts. You get a great workout and you don't have to be overly coordinated. She is very inspirational and positive, I just love her. You really don't need a lot of space do do most of the moves either. If it interests you, you can check out some video clips on you tube. There are quite a few on there. I also have a gym style elliptical trainer that I picked up second hand for a good deal. It is a great machine to get the heart rate going

You don't have to have any equipment at all but any little extra thing you can do will be beneficial. Keep an eye out on classifieds sites like kijiji.com. That is where I found my elliptical.
The Wii sounds like a good idea to get you up and moving. I wouldn't rely on it as your only source of exercise but is a great start for sure! I am getting a wii fit for my birthday this week. It looks like fun!