This product originally called Miracle Greens was among the first on the market and is still among the best. Its land veggies include beets, cactus, barley grass, and carrot. It has large doses of herbs, including ginger, horsetail, suma, astragalus, Echinacea, milk thistle and others. Read more about this product here...
EnergyFirst has added some herbal ingredients that are often found in green drink formulas, including green tea, Echinacea, and ginko biloba. I applaud the addition of MSM in this mixture, as this is a supplement that most of us need and few of us get. However, the bulk of the ingredients in this mixture are fillers, such as barley malt extract and brown rice syrup solids (filler and taste) and the greens are primarily spirulina and grasses. Read more about this product in this in-depth review...
This product, while on the expensive side, is almost completely without fillers of any kind. It contains just a bit of brown rice solids, but otherwise, it’s pure functional. It features spinach and other healthy veggie powders (kale, broccoli, cabbage and Brussels sprouts), plus fruit powders like blueberry, cranberry, pomegranate and papaya. Check out this article for a complete review of Berry Green...
A good mixture with healthy amounts of greens (spirulina, chlorella and barley grass), vegetable powders (carrot, broccoli, spinach and others), and anti-oxidants (fruits, beet root, milk thistle, pomegranate, green tea and more). The formula is very similar to Antioxidant Natural Greens (see link and compare), which has more flax meal and is, consequently, less expensive. The flax provides Omega-3 fatty acids, but also creates more bulk in the mixture, which lowers the manufacturing cost. Overall, this is a good mixture, but it seems a bit expensive for what you get.
In this installment on green superfood powders, I’ve prepared a handy comparison chart that shows the ingredients of several products side-by-side. This makes it easier to compare and contrast the different products. Although this completes my series on green superfood powders for the time being, I will update these various comparisons and listings as needed, so check back from time to time to see the new additions and updates.
Greens Pak offers a fairly typical mixture of greens (grasses and spirulina), veggie powders (carrot, broccoli, spinach juices) and special herbs (in this case grouped into an “antioxidant blend” including milk thistle, red beet root and aloe vera leaf powders). There are good amounts of all of these blends and a good amount of filler, which is Lecithin in this case. The product comes in handy, single-serving packs, but the serving size is only 7.5 grams, about half of what other brands suggest. 
This formulation is quite cost effective. It is high in Spirulina and Chlorella, two very nutritive ingredients that don’t cost a fortune. The formula uses nutritional yeast (a kind of brewer’s yeast) in the place of a filler to bulk-up the mix. Some people will prefer this to the flaxseed meal, rice solids or apple pectin used by other formulators. Some won’t. 
There are more and more green superfood products hitting the market all the time. What you should know as a consumer of these products is that the quality of these products varies greatly and it can be difficult to judge one from another just by looking at the label. This article provides some insights as to how to read the labels and evaluate the contents of your green drink.