As far as a go go juice it's coffee for me. It has no chemicals, you know. All those canned drinks are nothing but chemicals / fake stuff.
I drink very strong black tea (with milk and sweetener) or iced tea all day long. If you brew it strong, the caffeine is significant.
I only drink tea. No rockstars, no coffee, no nothing. Tea is with no preservatives. I tend to eat and drink healthy things.