I loved 30 day shred, especially if you are just starting to workout or just want to switch up your routine. There are 3 different workouts on the DVD so it doesn't get boring either. I lost a few inches but wasn't really using it to lose weight, just switch up my workout routine so I could do something quick before work (about 28minute workout)
My fiance did insanity with some of the guys he works with, he played college football and said that workout was the hardest thing he ever did (and he was in decent shape when he did it). I think the insanity program is a great concept but it can be intimidating for some, however, it does give you great results