I have most of these so maybe I can help. First of all, you have to think about what you like to do.
Turbofire is a lot of fun, it took me awhile to get the hang of it. But once I did, I am loving it. It is basically kickboxing on speed. The package contains 4 steady state cardio workouts, 3 Hiit (15, 20, & 25 minutes), 2 stretch workotus, and 2 band workouts.
Bob's Workouts are very different. His are more circuit training. I haven't done them all, but His "cardio" workout involves weights. His Yoga workout is awesome...I highly recommend it. You can do a rotation with his 4 DVDs, but As much as I enjoyed them and thought they were tough, I could not see myself doing a rotation with just his workouts. I would use them with other workotus...IMO.
Tonique: Iihave her first one and the Second one (which contacins 2 workouts). They both are pretty much butt and leg workouts. You start with some cardio and then you do a ton of lunges and squats. The first one has an added mat workotu, that I really like. The second one has 2 different 50 minutes workouts. She uses 2# weights in both of them for sculpting.
Michelle Dozios: I don't have hers...yet. They are on my wish list. I have heard that they are similar to intensity as Cathe's CCC, even the strength one, I believe, involves a lot of cardio.
So, think about what you klike doing, so that you don't get bored (I like variety) and your goals. If you want to slim down, them maybe Tonique and Michelle Dozios. I think Cathe's new workouts will also help with that...high reps, and lower body blast. Turbofire is just a lot of fun, and you will burn a lot of calories...I am not so sure about sculpting results. I like to do her cardio.
Anyway, good luck with your choices!! I hope I helped, and feel free to ask more questions!!