I hope some others chime in to help you, but here are my opinions:
Pure Strength is a good series, but in my opinion not as good as Slow & Heavy or the Pyramids. Another thing: Cathe says you shouldn't do Slow & Heavy too long because it requires a lot of concentration that's difficult to keep up for very long. It's mainly a plateau-busting tape.
The Rhythmic Step DVD is a good one to have if you like Cathe's more difficult cardio. Rhythmic Step is difficult to learn but if you catch on to Cathe's moves quickly (and a lot of people do) then you'll love it. It also has MIC and the original Imax, which are cardio killers! They will put you into great cardio shape, but for my money, Rhythmic Step is more fun, and so are Imax2 and Cathe's newer cardio titles like Step Blast or even Cardio & Weights.
Power Hour is a lot like Muscle Endurance, a good, total body muscle endurance workout (many reps, lighter weights), but I tend to favor the muscle-building workouts (heavier weights, fewer reps). You might prefer the endurance style.
Other people may give you different advice, but I say wait for Hardcore. There are a lot of new titles in that series that will do a lot of different things. Save your money and see if you still need more titles after you receive Hardcore. If so, then go ahead and get the older titles. But I would wait and see.
