Plyometrics will always be my favorite P90X workout. It’s as tough as you make it, which is not too tough for me right now. I modify all the moves that put pressure on the knee and go at my own (very slow) pace, and it’s great. You break out a sweat, but it doesn’t feel impossible like Insanity cardio.
I’ve set reminders varying by the day of week on my phone telling me to do these workouts. Pretty sure I will miss more than a couple, but this way hopefully not too many.