If you are going to buy a water filter, I will recommend PUR Black/Chrome “Advanced” Vertical Faucet Mount, it is a very popular water filter as of now, however there are many brands that produce water filter but usability, life, cost are the main things when you want to buy an product online. Brita and PUR are 2 of the most popular brands as of now, they are directly and easily fixed with faucets and there are many other features that you will love when you buy this product. If you are using these filters make sure you are replacing them regularly, it is recommended to change the filter after 100 gallons. According to my experience 100 gallons can last for around 6 weeks so when six weeks are passed, you should think of changing the water filters as well. When we talk about the prices then they vary in price, it happens that sometimes you get a good product by spending very little money. I will say that you shouldn’t use bottled water as it is not very good to your health, you should drink filtered water to ensure that your health is good and you are not affected from any bacteria.