Water:
Its 100% h2o, it really helped to hydrate me in my time of thirst. I find it from the faucets in my house but that can have additives I don't care for. Another place to get it is the filtered dispenser on my fridge. I also have a water cooler that uses 5 gallon jugs of mountain spring water. all can be fairly cheep sources of the beverage with the 5 gallon jug refills costing a mere $1.50 for "5 GALLONS of beverage". The rest coming with a subscription plan you buy from your local water company, and they deliver it right to your house!
and yes the answer is 98% of what i drink is water.