Earl Grey without milk or sugar - but not the tea bags. It has to be leaves. I't might be my imagination, but there's a world of difference. If the choice is between tea in bags and coffee, I'd probably go for the coffee. But I'm somewhat of an insomniac, so that makes sense.
An interesting fact I picked up watching QI - even though many people would say that tea contains more caffeine, this is not quite correct. Tea leaves, per unit of weight, would contain more caffeine than the same amount of coffee beans/ground coffee/whatever. However, seeing as tea leaves are very light, there is actually more caffeine in a cup of coffee than a cup of tea.