Buy whole bean and grind it just before you use it. The aroma and flavor will be at its peak.
Do not store beans in the freezer. This will separate out the oils in the coffee and make it more bitter. Just use an airtight container, in a cool (60-70 degree) place.
Use filtered/distilled water.
The single most important thing (beyond the coffee itself) in changing the flavor is the water, the difference between unfiltered tapwater and that which goes through a Pur filter can be tremendous, depending on the water coming out of the tap, and you can readily smell and taste the difference in the coffee.
Coffee pots which are fast tend to overheat the water and also bring out the bitter and acidic qualities in the coffee.
Believe it or not, the best coffee I have had (low acid, smooth) for any given bean comes from cheap drip coffee makers which do not brew as fast but brew a better cup at lower temperatures.
In my earlier post, the first link is my personal favorite after having tried coffees from all over. It is strong, but low acid, full flavored, and I like it better than any others I have had.
But, as someone mentioned, picking the best coffee is like picking the most beautiful woman, everyone's tastes vary. Check out the site (www.CoffeeBeandirect.com), they have many coffees to suit virtually every taste and reasonable prices. I have done business with them for a few years now and have never been disappointed.
Life is too short for bad coffee.
Thanks for the advice. I always thought storing the freezer preserved the beans.
I agree with the distilled water to make the coffee with. I like to buy Costa Rican beans already roasted but fresh, and grind them before each small pot. I have a big ceramic cup that holds a potful from the little coffeemaker.
The coffee is so good, plain black when fresh brewed, a bit of sugar when older than 1/2 hour.