We get our water report every year for the town we live in. It says the water is fine, so I use it to cook with and make things like Iced Tea, or lemonade. BUT, since I don't think it tastes "pure" when I drink it plain , I invested in a brita filter and I love it. I just keep the jug full at all times for when I want a glass of water.
I would not waste my money on bottled water, I've seen many reports that its little more than filtered tap water, not really "mountain spring" water.
Also Nena10, to purify water, boiling it is really not all that is involved. That will kill any organisms such as bacteria, but it has no effect if your water has minerals like copper or lead. In fact, it intensifies it. The only pure water from boiling is the "steam", which is called distilled water, but its difficult to trap and transform back to "water"....so a filter is definitly your best bet.