My favorites...
1. IMax 2 - the one I can ALWAYS reach for and finish, no matter how much I don't want to work out.
2. HSTA - kicks my butt everytime, but it's fun!
3. Circuit Max
If non-Cathe workouts I have to say the P90X series fits in there somewhere - if only for the sheer joy of watching Tony do Plyo Pushups.