Coffee, all the way. I'd like to offer this quote in support of my decision:
This coffee falls into your stomach, and straightway there is a general commotion. Ideas begin to move like the battalions of the Grand Army of the battlefield, and the battle takes place. Things remembered arrive at full gallop, ensuing to the wind. The light cavalry of comparisons deliver a magnificent deploying charge, the artillery of logic hurry up with their train and ammunition, the shafts of with start up like sharpshooters. Similes arise, the paper is covered with ink; for the struggle commences and is concluded with torrents of black water, just as a battle with powder. ~Honore de Balzac, "The Pleasures and Pains of Coffee"
Every writer needs coffee.