For nonbiased video reviews, try
www.videofitness.com ,
www.amazon.com ,
www.college-video. com (you may need to type in this last one. The link never seems to work.) . Read the reviews to see which tapes seem to match your personality.
What are you looking for--strength training, flexibility, aerobic? I walk, ST, and do yoga. If you decide on ST, look into The Firm tapes. I hear these are great.
For yoga, there is the aerobic kind, like Astanga, or the relaxing kind, and many types in the middle. If you're really inflexible and new to yoga, I suggest Yoga Zone's Introduction to Yoga. Cueing is great for someone who's never done yoga. You can "move up" from there. If you want more flexibility try Rodney Yee's Yoga for Athletes. For more more aerobic a workout, check out power yoga tapes.
Be careful, though. I have about 20 yoga tapes (done about a dozen) and very few of them offer good cueing and instruction for a beginner. I do ffind the Yoga Zone tapes to be excellent in that department, though.
Pilates is also a good exercise for increased flexibility and wellness. However, I don't have a tape recommendation for that.
REC
walking, ST, yoga