H ieveryobody, as a video fanatic, I wanted to post a few links to great sites you might like:

Video Fitness
Collage Video
Unofficial Joyce Vedral Forum
Firm Believers forum

How about your favorites?

Cathe Friedrich

She has long video clips of her videos. IMO she is one of the best in the business. She is a little more expensive than others but the quality and production of her DVDs are top notch.