My favorite is green tea! I drink green tea before a bike ride to get me energized and hydrated and also to help with boosting my metabolism. If I go on a morning bike ride and need the boost, I will drink some coffee. I usually try to stray away from any strong energy supplements. I take some nuts or a banana to give me a boost if need be. I highly recommend preparing cold-brewed green tea by leaving 2 bags of green tea in a water container overnight. It is refreshing, amazing and gives you great energy and hydration for a bike ride.
I like green tea too. I prefer adding milk to make it creamy. It tastes smooth and refreshing. This is probably why they call it milk tea.