Zest Teas are the most caffeinated teas in the world.
They have about as much caffeine as a cup of coffee, or 3 times the amount of normal teas.
They also taste delicious. Flavors include Apple Cinnamon Black Tea, Pomegranate Mojito Green Tea, Blue Lady Black Tea, and Earl Grey Black Tea.
site link: http://getzesttea.com/