I agree with everything so far. They're ALL good workouts. Find one you think you can do, but most importantly, STICK WTIH IT!!!!!!.

And as Atlas said, whichever one you pick, be careful. If you've been inactive or not exercising much, you'll have to do a warm up/ramp up before going full bore into which ever program you do. To include some stretching, basic resistance movements (pushups, squats, curls, bench dips, lat pulls, etc.). Otherwise you'll be so sore from the first few workouts you can run the risk of just dropping it and getting frustrated from the pain/soreness.

For the pull up/chin up exercises, you can use a dook anchor.

Although a gym with dumbbells/pull up bar would be ideal, it's NOT required for P90X. I did it on the road with resistance bands and STILL got a good excellent results. You'd be surprised in how tiny of a hotel room I was STILL able to rock the crap out of Plyometrics, I friggin' love that workout!!!!!!!

Granted, some of the exercises with the bands required a learning curve to extract maximum result, as well as not waste excessive time switching the bands out when changing exercises, etc.

And to the OP, remember, all the ads/infomercials are there to SELL a product. Yep, you'll get a killer workout out whatever program you go with. But bear in mind, some of those before and after shots of people may not be telling the WHOLE story. As in, it may have taken MORE than one cycle of the program to the results depicted in the ads.

As I mentioned though, sticking with it and getting it done is the key. And remember, diet and proper rest plays just as much of an important role as doing the workouts does.