It is often a matter of personal preference whether someone goes for bottled water or tap water, though there might be some information here that could sway the argument either way.
There's just a lot of bottled water types to pick, all with different sizes and amounts to pick from.
Some people opt to buy the expensive, brand name stuff while others are willing to just go with store-name brand water.
Whether branded or not, it eventually comes down to personal preference more than actual water quality.
It might involve availability or cost, but at the end of the day, the water itself doesn't matter - just the one you happened to get used to.
Interestingly, the plastic packaging of a water bottle tends to leech poisons into the water.
This results in safety levels that aren't too different from tap water, as the water remains contaminated somehow, albeit from a far different source.
This makes bottled water far less appealing for a lot of people.
Despite this drop in appeal, people still hang with bottled water simply because it has far stricter safety rules.
Bottled water, in a vacuum, remains much cleaner than tap water simply because it goes through more filters than tap water does.
Tap water might still contain all the fecal and e-coli nasties that tend to pool in it, while in bottled water there only remains a minimal chance of actually drinking anything contaminated or harmful.
Tap water definitely loses out in terms of safety or even basic cleanliness, due to the aforementioned potential contaminants, but of course that depends on the area you're in.
There's a reason water filters are rising in demand - they give you full control of your water quality.
They're easy to find and you can have a plumber install it if you're having trouble with it.
You can also go to a local store like Bed Bath and Beyond or Wal Mart and get a filter that does't need to be applied to the sink.
They're pretty cheap and give you assurance that your drinking healthier fluids.