Usually my drink of choice is Cuban Coffee With Milk (technically, its a modified espresso, but tell that to any Cuban and well....things can get ugly).
But when I need to pull all-nighters, or I need the kind of forced wakefulness that would drive most men mad, I turn to a little formula of mine that I lovingly refer to as "Brain Bomb". Half a can of NOS energy drink, a little bit of Arizona Energy RX, and a touch of Mountain Dew (for flavor) and voila! Instant energy (or at least a semblance of life).