How terrible are energy drinks for you?

I LOVE them. Im 19 and only have drank them a few times when i was younger but now i have one almost every morning if i have some in my fridge. I know the taurine and stuff is bad but the caffeine and ginseng give me a boost and i swear boost my metabolism and help me get stuff done faster. It also helps me with workouts :) Is one a day really bad? or should I keep doing what im doing?