[jyl]

I have done both.

Home gym:

For cardio, assuming you can't do it all outside (weather, etc), then one machine is all you need. Elliptical, bike, treadmill are the most common, I think it is just a question of preference, you can get and keep your heart rate up with any of them. But these are all leg-only and cardio-only. I think the best would be a rowing machine, it works legs-core-arms, is a resistance exercise as well as cardio, helps strengthen your back, and depending on resistance chosen can be (doesn't have to be) a much harder workout than any of the above. Buy exercise equipment used.

For resistance, you can do a lot with bodyweight exercises on a piece of mat. Add a pull up bar and a couple sets of gymnastic rings/straps, at waist and ankle height, and you can work nearly every muscle group you'd care to. Then add a couple sets of dumbbells for overhead stuff. This can all cost <$200 and take up very little space.

Gym:

There are so many, ranging from high pressure meat markets to relaxed family places, and the price varies a lot. We belong to a neighborhood gym, $70/mo for the whole family, no contract. At some chains that would be $200.

I like the classes, for instruction and motivation. I go to spin classes weekly, I'd never work that hard on a bike in my basement, and there aren't hot young women in Spandex bobbing on bikes in my basement. I'm going to try yoga, since I know nothing about it, having an instructor will help at lot.

If you go the gym route, maybe launch yourself into it, use a personal trainer and/or sample all the classes for a couple months, learn as much as you can, then decide whether to continue on in the gym or at home.

Oh - another suggestion - join our PPOT weight loss & fitness challenge - see the sticky thread.