There are two species of coffee, Robusta and Arabica. Robusta coffee grows well in hot and low water environments and is the most plentiful and cheapest type of coffee. Robusta type coffee is usually machined harvested and processed using a dry method. This is why Robustas tend to taste "dirty". Robustas tend to taste "peanuty" too. Robusta coffee has a higher caffeine content than Arabicas.
Arabica coffees are grown along mountainsides and in areas with abundant rain fall. They are harvested by hand and processed using the wet method. Arabica coffee tend to have "winey", "sour", "acidic", and cleaner (than Robusta) flavors. Since they are picked by hand the flavor quality tends to be more consistent than Robusta coffee.
Gourmet coffees usually are 100% Arabicas thus are the most expensive. The cheaper the coffee the more Robustas is used in the blend.
What tastes good is cultural. I know someone who prefers to drink coffee that has a high percentage of Robustas. I personally do not like the taste of the coffee from Brazil. I prefer a good quality medium to dark roasted Columbian coffee. I like good quality coffees from Kenya, Costa Rica, Hawaii, Kona too.