Most people i know that prefer bottled water prefer it because of the chlorine taste in their city tap water. Most bottled water goes through several processess including softening or reverse osmosis which can impact the taste quite a bit. They often remineralize the bottled water and add flouride as well. They do make undersink reverse osmosis systems for people who have taste or odor concerns from their tap water, essentially getting a similar quality to bottled out of a tap.