What brand of water is better for your body
I dunno about you but I drink tap xD
A water filter would be the most cost effective solution for this situation.
If you are drinking enough water, you will be okay. It doesn't have vitamins or anything. Just get as much as you should to stay hydrated and get your healthy vitamins elsewhere.
Tap water. Most bottled water is just tap water anyway, from somewhere else. You could get a filter pitcher for your tap water if it tastes odd, but bottled water is pretty much a waste of money.