Coffee. In a mug, and almost always instant with milk and no sugar. Although for special holidays such as Christmas I dust-off our coffee filter machine and treat myself to filtered coffee with cream; and when we need new filtered coffee buy the beans fresh and grind them in our electric coffee grinder.
Also, during the seasonal holidays, while we're using the coffee filter machine I'll also add a bit of Whiskey to the occasional mug to make it 'Irish Coffee' as a treat.
When on our annual holiday in France I always ask for Cappuccino as an almost guaranteed way of getting a half descent cup of coffee with milk. Otherwise if you just order coffee you end up with a very tiny cup of black coffee (with only a mouthful of drink in the cup); and if you ask for a grande (big) cup with milk you still only get served a cup (rather than mug) of coffee, and get funny looks from the restaurant staff for wanting milk in the coffee.
As regards tea, I just don't like it. Even though tea is traditionally the national drink of my nation (England) and according to a recent YouGov opinion poll 52% of British people still prefer tea. In that survey 35% of Brits preferred coffee, and 11% liked both.