I have REALLY gotten into sampling energy drinks, and I have sampled most of the popular ones:
Red Bull (reg & SF)
Monster (reg, Lo-Carb, Java, Khaos, Assault)
RockStar (reg, and Low Carb)
I really dont realy know what to try next since there are 350+ energy drinks out there, plus I am limited in my area to only like 75 of 'em.