I am now ready to accept the pummeling to come... but I believe the most healthy energy drink that is in production is XS energy. No sugar no carbs and a couple caffeine free flavors... The main energy from these drinks is the b vitamins.. there is 4900% recommended daily value of b12. The coolest thing about the b vitamins is the fact that they are water soluble rather than fat soluble so any that is unused is excrexted in urine, not stored in fat. with the no carbs or sugar... it is also good for diabetics.. I know this only because my dad drinks them all the time. And yes he is diabetic.
Yes I am biased. I sell XS Power nutrition, including XS Energy Drink.