This show is fun to watch for the transformations from funny-looking to fantastic. I enjoy and fully endorse the message that people of all body types can look good when they dress with self-respect and a bit of design sense.
What bothers me is that this show promotes the idea that if you want to look good, you have to spend lots of money. Only once have I seen anyone on this show enter a secondhand clothing store. (In that case it wasn't for budget reasons, but for going-green reasons, which is also a positive message.)
The put-downs in the show make parental guidance important. If you watch this with your kids, talk with them about whether the way Stacy and Clinton talk to the subjects is appropriate. Encourage kids to look for people's positive qualities of talents and character, and not to judge them negatively for how they dress. Despite the consumerism and the mean words, I call this show a net positive because teen and tween girls sorely need the "beautiful in any body" message that What Not to Wear conveys.