Given the puzzled response I usually get to my request I always thought I was the only one drinking ginger ale on board. Would prefer ginger beer, but that's impossible to find on any of the middle eastern airlines I fly. Other than that, it's always a glass of apple juice and a glass of orange juice from the carton for me, no ice.
Rarely drink alcohol when flying, but sometimes a Bailey's just calls to me.
Qatar business class has chai tea bags, and I'll drink my way through the plane's entire supply on a long haul flight. They also do a really nice laban as a welcome drink, and I can't say no to a glass of port with the cheese plate.