There are literally hundreds, perhaps thousands, of "water filtration" products on the market. If you have well water, maybe a half-dozen of those products are worth considering and if you have a septic system that rules out a bunch of those.

Reverse Osmosis systems are a problem for the combination of a well and septic system, as RO wastes a huge amount of water and all the water that is wasted gets dumped into your septic system, so you are unnecessarily stressing both your fresh water supply system and your sewage system.

For that situation, there are only two water treatment systems I would recommend, the Pure Effect ULTRA-WH-W being the better of the two. One specific reason for that is the ULTR-WH-W has an anti-rad cartridge which can handle Radon in the water.

Overall, the pure effect filters are better thought out to deal with realistic water issues--they even help to alkalinize the water, which has demonstrable health benefits.