Again, really, there is nothing else to drink, besides sugar water and fake sugar water?
You should try plain water. It's delicious, refreshing, hydrating, and vital. Make sure you don't add any other nonsense like fake-fruit powder or anything. Just a tall glass of fresh water. Some argue about the temperature it should served at, but really, any temperature between freezing and boiling is better than soda pop.
Drink as many glasses as you need. Again, people argue how many is too many, but your body can tell. Plus it will make your kidneys work (less chance of kidney stones), give you better skin, and generally better digestion.
Finally, if your local source is appropriate and if there is no current restriction due to uncontrolled events, use tap water instead of bottled water. It's got higher regulation for safety and is cheaper overall.
I don't live in the States, and this idea that there is nothing out there but sugary drinks baffles me. I wish I understood why it is so ingrained in your culture. Even here in Canada, soda pop is quite common but people know of the alternatives.