Yerba Mate!
It gives you energy in a different way than coffee. Also it's very healthy, even more than green tea.
Here's a article:
http://www.brainready.com/blog/yerba...ee_which_.html
zOMG!
Mate' first came to my attention because some people on the Chronic Fatigue Syndrome boards I am on were talking about it giving you a "clean" burst of energy without the icky letdown common to coffee and tea. I actually LIKE the kick from coffee, but found that mate' did give me some nice sustained energy, especially in the afternoon when I tend to get draggy in the office. (Plus, caffeine not only hsa not been proven to be bad for fertility, but it had been shown to make sperm swim faster. Hyah!