I prefer my water from a thousand foot well and at least 10,000 years old, but deep wells are expensive and around here it might be salty due to the impact that formed the Chesapeake Bay. All the wells around here are shallow ground water wells infused with minerals. My well has lots of iron and poor taste, so I haul in bottled spring (treated tap) water, which tastes ok, but I hate the idea of the plastic it comes in. I should probably get a Brita and drink the well water.
A Brita pitcher costs $20-$40 and comes with a filter and usually a replacement filter. Reverse osmosis is a super neat idea, but a couple to few hundred dollars for the equipment plus installation.
An activated carbon filter removes 10-15% of all contaminants or total dissolved solids and and can absorb a range of toxins, drugs, viruses, bacteria, fungus, and chemicals found in water. Activated charcoal replacement filters cost anywhere from $20-$30 (in 3 to 5 packs, but also available in bulk) and should be replaced every 6 months to a year.
Reverse osmosis removes 95-97% of total dissolved solids, and has a very high effectiveness in removing bacteria (Campylobacter, Salmonella, Shigella, E. coli) and a very high effectiveness in removing viruses (Enteric, Hepatitis A, Norovirus, Rotavirus). RO replacement filters come in pairs for around $50 and should be replaced every year.
I have never tasted reverse osmosis, but it removes so much I wonder if it is bland compared to activated charcoal. Distilled water doesn't taste as good to me as spring water.
I think all in all, activated charcoal is good, reverse osmosis is best. I could probably save up for a reverse osmosis system, but I'm only leasing the sink.