Water or 100% fresh squeezed fruit or vegetable juice is healthiest. If you can't get fresh squeezed, try for 100% fruit/veggie juice that is not from concentrate. These won't have any artificial additives or sugars added to them.

WATER! And lots of it. Add a slice of lemon, orange, lime, or even grapefruit if you like and pour over ice or just straight from the cooler. Its good for you and will help flush out the toxins in your body. As an alternative with a fizz, I also enjoy San Pellegrino periodlically when I get a craving for soda. Try it with some sugar free Torani Raspberry syrup and its like a refreshing Italian soda.