Water Filtration System

The wife has asked me to look for a water filtration system for under our kitchen
sink that will act as our drinking water.We currently use reverse osmosis water that we purchase and use in our water cooler,instead of purchasing a new water cooler and weekly spending money on water she has decided we might as well buy our
own system.I've been drinking distilled water for over 2 weeks and plan on doing it
for life but she hasn't yet bought into distilled water so i have to honour that,
anyway does anyone recommend a system that is affordable yet provides reasonably
clean water.