Let me point you in the right direction. I studied this topic extensively years ago, so let me summarize what I learned.
1) Distilled Water: This is the purest, cleanest water you can get.... period. Water is first boiled, and the condensation is collected. If done properly, the water is free of all germs, particles, metals, etc. You can purchase a counter-top distiller, which continuously boils waster and distills it for you. It's very expensive, and not very energy-friendly. I would not recommend distilled water in plastic jugs, as the plastic containers leech stuff into the water.
2) Reverse Osmosis: If distilled water is not available or practical, then reverse osmosis is the 2nd cleanest water you can get, and very nearly as clean as distilled, as long as you're starting with tap water. A key benefit here, is that you can get a "whole house" reverse-osmosis system, which will simplify things for you. All the members of the household will get continuously reverse-osmosis purified water from faucets and shower heads.
3) Under-sink, or Refrigerator based filters: After the first 2 options, the 3rd best option is to use a large, sophisticated filtering system. The best kind are the ones that mount under the sink, or the ones that are built into modern fridges. These get kind of expensive, as you need to keep buying filters.... but a quality filtration system will get out most of the bad stuff.
4) Portable water filters: These are the last option you want to use, because they really aren't that great at cleaning much from the water. Some of the high-end ones may be okay, but stay away from Brita. Brita mainly only filters out chlorine, which is the element with the strongest taste and odor in tap water.