Have you ever considered getting a Wii, and getting WiiFit? I know it doesn't take the place of going to a gym, but it really can help get you motivated to start exercising, and once you get good at the Wiifit, it's a lot easier to start adding other "real" exercises to your routine as well.
For example, I try to walk (really fast) about 4 miles a day. I also like to work out with weights in my house. For me, exercising is not that hard to get into.
My wife and kids, on the other hand, aren't exercise buffs. After getting the Wiifit, all of them love to spend time (up to an hour each) having fun and getting in a lot of exercise on the Wii. It really does make stretching, strength exercises, balance, endurance, etc... a whole lot of fun. It takes away the whole "I don't feel like doing this today", and replaces it with "I can't wait to get on my WiiFit today."
You really might want to check into it, it might be just what you're looking for to help get you motivated to get more fit.