Wife works with a surgeon who will allow himself to have a coke only when he has a couple days off in a row. It's his little "treat". Says his hands will shake for over a day after drinking one can. I drink about 5 gallons of black coffee a day. Can't stand "sweet" so those energy drinks are a big pass for me. Although I used to like redbull and vodka once in a while, but havn't had one in years.
I used to be a double added shot of espresso kind of guy when I worked next door to a coffee shop, but now if I drink half a can of code red mountain dew I get jittery... really comes in handy when I'm dragging ass and actually *need* a boost instead of using it just to get through the day.