Free the tea! Loose leaf is the way to go. No guessing what's in it either. But go organic when possible.
If you've got an herbal/alternative medicine store in your area, they'll hook you up. Or just go online. Egyptian Chamomile is the best. I also like lemon grass, lemon balm and licorice root (good for the throat), Rooibois is also satisfying too.
Chinese and Japanese green and oolong tea are my picks. Iron Goddess and Gyokuro/Matcha are my favorites right now.
For the coffee fiends, I suggest yerba mate (that's what I'm drinking atm, it's great when made with a French press), matcha tea and roasted carob tea.