Gotta have that first cup of coffee in the morning to wake up. Without it I feel sluggish and headachy all day - partly due to the dependence on the caffeine. Also i drink Diet Coke in the afternoon and evening, and without it I get pounding headaches. My general doctor recommended caffeine to help with migraines.
I do like tea, though - I've got peppermint tea on hand for soothing my various gastric problems. But it just doesn't work as a hot drink for me first thing in the morning.