Generally you get a fountain drink (soda, lemonade, etc.) Some places will give bottled water. I imagine a regular coffee would be allowed. I highly doubt you could get a speciality beverage or milkshake at a CS.
I think that we always ordered large drinks but not sure. We always ask for no ice in the sodas and then I ask for a couple of cups with ice. You would be surprised how much more soda that you get. Not one of us leaves thirsty.
Dreams Unlimited Travel is committed to providing you with the very best vacation planning experience possible. Our Vacation Planners are experts and will share their honest advice to help you have a magical vacation.