I drink my coffee black.
I always try to use Eight O'clock "Original". It is the highest rated readily available coffee in the states.
Much of the time we mix it about 3 parts Eight O'clock and 1 part Bustelo. I learned about Bustelo from Mrs. RedRyder. It is an espresso grind and makes a very stout coffee if used by itself. If the Eight O'Clock Original is 100% Columbian. If the Original is not available, the Eight O'clock "Columbian Peaks" is also very good.
Keep in mind that coffee is 98% water. The water quality makes a huge difference to your coffee's taste. Distilled water is not a great option and neither is water that is too hard. Distilled water is not recommended as it will consistently deliver a mediocre bitter cup of coffee. Cold tap water or charcoal filtered tap water is generally the best. A charcoal filter will remove chlorine and other bad taste and smell if you have hard water.