Water with natural flavoring added if needed. You can drink organic juice that contains only 100% juice, but not what they call drinks that may contain only 10-15% of real fruit juice added. The rest is sugar.
Sprite is actually the healthiest soft drink you can have. There's no color in it so it doesn't harm your kidneys, and it can also get rid of the acid reflux better than Tums can. Sprite isn't too healthy to be drinking all the time, but once in a while isn't bad.
Drink water, fat free milk, my sons dentist suggested sugar free Crystal Light but it is just flavored water. You can drink tea. You can make fruit juice yourself. Blend watermelon or cantaloupe in a blender with water.
Milk is great for you. Unless you are allergic milk fat is healthy and there are 1%, 2%, and skim or fat free. Packaged juices arent good but fresh juices are wonderful. Water is what you need to drink most of all, tho.