Best/effective system that can filter water properly

So I am trying to make changes in the house. Trying to drink more cleaner water. I am trying to find out more information about a filter system I can get for drinking water. One of them was in amazon called ISpring reverse osmosis for $179.99. I got good review but wow five different filter. Does anyone know if thats a good one and what else other their . How can I find out which one is actually efective. Since I want something that only takes out the bad things off the water but still able to keep the good minerals.