Oh this is so hard! I love them all and can't pick a favorite strength training. My most used series is RwH, my all time favorite cardio is HiiT DWP and my favorite Cathe that I almost never use (just because it doesn't fit in well with how I schedule my workouts) is Athletic Training. I haven't done a lot of Cathe Lives, but of those that I've done, I love Strong Upper Body and CCC Live.