I love drinking tea to stay warm, but it doesn't really keep me awake. I love the greens, especially the green jasmines and other lighter, crisper flavors. Sometimes I like the fruity greens, but I have to be in the mood for it. I also enjoy rooibos and honeybush teas, and have recently started enjoying mint teas.
But, if it's staying awake I'm after, then that's what sugar free red bull is for. You could say I have a slight addicition...but hey, it's the only energy drink in the world with two F1 teams!