How about milk. Liters of milk.
Pasteurised milk mind you, the sterilised stuff you can keep outside of the refrigirator tastes nasty.
I drink about 3 to 5 0.4L cups a day, so it can add up to 2 Liters.
Otherwise, a cup of tea in the evening. Preferably Herbal or mint.
On occasion a cup of coffee, but with lots of flavouring, milk and sugar.
I like sodas in summertime, or when I'm out eating.