Hmmmm, interesting thread. Being a teenager, energy is in constant demand for me, which really sucks at times. I've used 5-hour energy before, and it helped, but I didn't notice a huge boost. It was barely able to give me enough energy to mow the lawn after an all-nighter I pulled. What I like to do to keep me awake and energy filled is to drink water, Gatorade when I need it, (like when I'm working out), eat food, and listen to some very loud music. What I need to start doing is get A LOT more sleep and to take more vitamins.
IMHO energy drinks are just sodas with extremely high sugar content and a bunch of other stuff that will jack you up like a spider monkey. AMP worked for me once, and I had an awesome day snowboarding because of it, but my stomach and intestines hated me for it later.