Hi Janna,
I'd have to say that all 3 workouts really are a "must have" for their own special qualities.
There are so many different ways to use BodyMax it makes BodyMax a "must!" You can go for the total 90min package, break it down to an hour with just the leg circuits and upper body, or pair the upper body and leg circuits seperately with other workouts.
PowerHour is a "must" for me because I enjoy barbell workouts, there are some db's thrown in but its primarily a barbell workout and a great endurance workout!
MIS is just a really great total body workout. You can lighten up or heavy up as needed. The pace is just right for either.
Donna
Fitness~ It's a journey, not a race!