Tap water isn't always that yummy to drink, but you'll often find that by using a Brita system (or another filtering system) that you can get safe and better-tasting water to drink. It's still far cheaper to do this than to buy bottled water all the time.
Or, if you prefer bottled water - check around to find the best deals. Pricey brand name bottled water can easily be $2 a bottle or more! But, you can get delicious spring water at a fraction of the price if you check stores in your area and compare prices.