Chap...it kinda depends on what you like? My list is a bit different than Mari's but I know she and I like alot of the same kind of workouts. For cardio...I love PlyometricsX as it is a great interval workout, CardioX is short and not real intense. KenpoX is okay (not real intense), but during the rotation I would substitue Cathe for KenpoX sometimes.
YogaX and StretchX are good to do once a week I believe. This was my first experince with Yoga and I did get some other yoga workouts. The Stretch (which is 60 min) I loved after my long runs on Sunday.
For the weights: Shoulders & Arms
Legs & Back
Shoulders, Chest & Triceps
Chest & Back...thats the order I like them
Core Synergistics I think is one of the best core workouts out there. AbRipperX did wonders for my abs....finally found that 6 pack...

...so not sure which ones I could live without....KenpoX,CardioX, Chest & Back...

...Carole
PS...don't they have video clips on their site???