Beyond the pure flavor considerations, intangible qualities like presentation and a water's story should be taken into account when choosing your bottled water. The bottle plays an important role in the overall perception of the water. Since water has no notable visible characteristics of its own, the bottle has a remarkable impact on perceived value. Matching the presentation to the venue or event may have no influence on the actual taste (as any blind water tasting will tell you), but doing so can significantly enhance the experience, or be detrimental to it.
Because water is a universal solvent, rainwater collects particles and chemicals even as it's falling. Geological strata only add more to the composition the minerals and trace elements of the local area give each water its distinct terroir. Underground geology may filter water for decades or even millennia; when the water finally emerges at the source it has terroir.
There is no such thing as a “best water,” just as there is no best wine. Very few people would ask “What is the best wine? The joy of being a foodie is understanding that wine should be enjoyed for being different and providing different experiences in a variety of contexts. What is the best wine? I would answer this by asking, “Is it Summer or Winter? What am I eating? Am I alone or in company?” In the same way as there is no best wine, there is no best water and we should not look for it but rather enjoy it as a natural product with terroir that expresses many different experiences.