First, I would definitely recommend DVD over VHS if that is a possibility for you. The DVD's offer mixing/matching, premixes, and the workout blender so you end up with many more workouts options.
If you like kickboxing, I think KPC is a good place to start. It you go DVD, you also get Legs & Glutes plus all the bonuses. Powerhour is a lot like Bodypump so that is a good choice if that is the type of workout you are looking for. The DVD also comes with MIS (strength training) and Bodymax (step, circuits and strength).
I would also suggest watching the video clips to help you make a decision. Of course, once you get hooked (and I know you will) you will want them all }( Good luck and welcome!
JJ