Sure, water is good for you, but water in plastic bottles can be bad for your wallet and bad for the environment. A daily bottled water habit can easily cost one person a few hundred dollars per year. Instead, invest in a high-quality reusable bottle -- I like glass ones from Lifefactory -- and fill it with filtered water. In just one year, that investment will help you recoup, on average, about $240. Cheers to the ecological savings!