Workout dvds are a very personal thing. To choose one you would have to decide what type of workout you are looking for. Do you like cardio style workouts, strength training, Pilates, yoga or a combination of a few varieties?
If you are aiming to lose fat and tone up then you might want to go for interval training workout DVDs. Interval training includes short segments of high intensity cardio followed by active recovery segments of strength training. There are a number of great interval training DVDs. The Firm bases most of their workouts on interval training and some of my favourite are The Hollywood Trainer Ultimate Cross Training, Kickboxing Bootcamp and Cardio Sculpt. You will only need some hand weights for the strength intervals, but apart from that no other equipment is needed.
If you also wanted to include some Pilates or Yoga on your lighter days, that would give a great companion to lengthen and stretch your muscles out. Ana Caban has some great Pilates DVDs ranging from beginners to advanced. There is one called Easy Pilates, which would be a nice one to start off with. And for yoga there is a series called Total Yoga the flow series, which once again has dvds ranging from beginners to advanced levels.