Coffee. I think for me it is the electrolyte which allows my brain cells to work; without it my brain would simply be an open circuit.
Coffee must be made properly, though. None of that instant nonsense or drip filter stuff which takes all the good oils and flavanoids out.
My own workhorse: a 1943 Sunbeam electric vacuum pot. Vacuum pots are the only way to go.
"Be ye not lost amongst Precept of Order." - Book of Uterus, 1:5, "Principia Discordia, or How I Found Goddess and What I Did to Her When I Found Her."