Actually, kakkoii, Rockstar ANYTHING is a sugar bomb waiting to completely obliterate your energy levels once it wears off. I've been sorting through energy drinks for at least 4 years now, and have finally settled on 2 1/2 that I will regularly drink.
Red Bull tastes funny and zingy in a strange way; too much sugar,
not down with fake sweeteners like Aspartame and Glucosamine either.
Rock Star, same deal. Read the friggin ingredients on any Rock Star, a ridiculous boatload of sugar.
The 2 that I regularly drink are:
Bing, made in Denver, CO. 40 calories per can, very little sugar, made with real bing cherry juice, and has all sorts of awesome herbs, vitamins, and minerals.
Go Fast, also made in Denver. Sweetened with natural Australian honey. Tastes like watermelon. Pure awesomeness in a can. Go Fast lite has 30 calories. Less sodium and sugar than most other energy drinks.
William, I'll definitely check out Vigor if it's available in CO.