I have done Insanity twice all the way through, losing a stone in the process, so could highly recommend it, even though I still wince at the thought of doing the Max Interval Plyo workout. As someone mentioned though, it does pound the joints, especially the knees so a mat to jump up and down on is recommended.
I've just started T25 this week and am enjoying the change of routine. I have found that calories burn at a similar rate to when doing Insanity, though obviously the workouts being shorter you don't burn so many. It seemed to be a good, well structured all round program through, with the short amount of time required daily a big attraction.
Another program I have followed and enjoyed recently is DDP Yoga. It's done by a former wrestler so is kind of a macho take on yoga, but is good fun, challenging and definitely helps build upper body strength too, without putting any stress on your joints so is especially beneficial for someone looking for a low impact workout that will still deliver results.