The first cup
Oh, that first cup from the pot, when the water is still nearly boiling, despite brewing for three minutes. The mug is almost too hot to hold in your hands (almost), and keeps steaming then entire time you're drinking.
The last cup, when it's nine in the morning and you think you've emptied the pot, but lo! the pot is not empty, well, that cup is great too, but the first is better.
There is something about the first cup of the season of that infinitely customizable winter classic. Low sugar, no sugar, extra sugar? Sure! Add a pinch of ground cloves or a few drops of mint extract. Pour what they call a "Schluck" in Stuttgart into your mug — a small shot of liqueur, like Grand Marnier or Creme de Menthe.