Distilled water is most likely your healthiest and most beneficial choice. Spring water is usually just tap poured into plastic bottles. However, being cased within a plastic container is always bad for any kind of water, especially after prolonged containment. All I know is that it has to do with the chemicals in the plastic. I know nothing more than this. Somebody could do a little research, perhaps? If you're picky about wanting minerals and vitamins, then you can always get a vitamin water of some sort. There are several brands out there. But, there are also tablets that you can add to water yourself, to destroy any harmful bacteria or chemicals. Tap water is disgusting. I hate it. I can tell a big difference between drinking bottled water, filtered water (on tap), and plain ol' tap water. I can't stand it. I usually go with spring and distilled. Distilled, even though it's your best option, is still bottled in plastic containers. I'm hoping somebody will chime in on the question risen.