UPDATED May 11, 2008
Amazing Grass is not one of the most robust formulas on the market. It consists mostly of grasses, which are good, but should not dominate a green drink mixture because they don’t offer as much nutrition as some other botanicals. Get a complete review here with detailed ingredients and comparisons with other products. 
Green Vibrance is an excellent formulation of spirulina, grasses and vegetable powders and it includes a nice selection of “extra botanicals” including bee pollen, ginko biloba, green tea extract, and Astragalus. Check out this review for more information, pros and cons, and comparisons with other green drinks on the market. 
A good green drink is made from freeze-dried plants and vegetables (and often fruit or fruit juices) and is actually a food product — not a supplement, like a vitamin or mineral supplement. Green drinks are basically food in concentrated, powdered form. The best ones use organic ingredients and combine a variety of food sources. This article gives you a good first-look at the booming green drink market and helps you make sense of the products and ingredients in them.
The health benefits of spirulina were not discovered at Klamath Lake in Oregon, but some of the first companies to offer spirulina products, under the name of “Blue Green Algae” came from this unique location. That was back in the late 70s and early 80s. Since then, companies have been raided by the FDA for “false claims” and other companies have sprouted up around the edge of the lake. Now there are four or five companies wild harvesting the algae from the lake for sale directly to consumers, through health food stores, or through network marketing structures.
If you've been keeping an eye on the latest buzz in the natural health world, you've certainly heard about the new super-juice coming from Hawaii, Tahiti and other tropical regions. Like many natural products that have received a lot of attention for their health benefits (and claims), Noni has been the subject of a lot of controversy, including a series of FDA warnings regarding health claims made about the juice. 
There are many great foods that are high in nutrients, antioxidants, or other substances and they all deserve their day in the sun. But these are my all-time favorites, foods that are really special—not just for health, but for many reasons. Check up on these power foods: 