I love steady state cardio! Here are my favorites:
Anything by Charlene Prickett (I still have and use her vhs workouts, step and floor cardio)
Firms: I love these because the older ones combine floor and step aerobics.
Gin Miller Simply Step, Basic Moves
Michelle Dozois Rockin Body Cardio Jam
Any Leslie workout
Stephanie Huckabee's PowerFit Cardio workouts (only 20 min long, great when I am short on time)
I forgot to add Kathy Smith's cardio workouts, especially the ones from her Project You set.
Sherry