Are there any video blog sites you think are especially good?

I’m putting together a video blog site using WordPress for my wife, with a medical/healthcare focus, and I’m looking for exemplary video blog sites to see how they do it. I’m especially interested in personality driven sites that have successfully integrated ecommerce (to sell related products via a Web catalog) and/or been successful monetizing/selling the video content clips to other sites. Are there any niche video blog sites you think are especially great?