Here's a nice little list.
Quacklist is a central repository of information about products, treatments, and doctors that not only skirt the edge of fraud, but willingly dance over the dark-side.
It includes ludicrous claims of so-called homeopathic therapies, unsubstantiated science, snake-oil, and fraudulent doctors.
It even has a small section on my favorite: informercials!
(via Bodyhack)