Of course one of the best parts of a flight is when the flight attendants come around with the snack and beverage cart, free soda, coffee, tea, maybe even cookies. As strange as it may sound, one thing that really annoys flight attendants is when passengers order Diet Coke. It's because the carbonated fizz in a Diet Coke takes a long time to settle at an altitude of 35,000 feet. Therefore it takes the most time to pour Diet Coke as compared to any other beverages on the plane!
Of course, you will still be served Diet Coke regardless of the flight attendant's preference, it's just something interesting to remember the next time you ask for your soda on board.