To all RB/Energy Drink consuments ... why do you drink RB instead of a good ol cup of coffee/tee? Please ... don't just write "it tastes good" ... no it don't. A strawberry or a cherry from the tree tastes good but not RB.
But besides that, energy drinks are an easy consistent way of getting exact amounts of caffeine. I drink pre-workout before gym days for that exact reason since it's a lot easy to get 200mg of caffine via one cold 10oz drink than trying to brew and chug two hot coffees at 8am.
Plus occasionally there's non caffeinated benefits; the Monster Rehab line really does seem to help in the morning after a night of hard drinking.