Generally coffee - black, no sugar and not instant if I can avoid it. Having said that, I've switched to taking a cereal drink (normally Barleycup, black, no sugar) in my flask to work; I think that a litre of coffee at work plus two or three more cups at home was a bit much.
If I do feel the need for a change, I've got a good stock of teas at home.
Wulf
ps. ... also Fairtrade when available
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