A visit to a coffee retailer will present you with an overwhelming array of options. As a reader of this site, I think we can put aside any instant coffee right away - it's just not the same drink.
There are many species of coffee grown but only two main types are widely grown for commercial distribution: arabica and robusta.
Arabica is a smoother, milder flavour and robusta is stronger but lacks the subtlety. Robusta is often blended in with Arabica to give it a stronger flavour.
Coffee beans evolved to grow beneath a forest canopy, and while growers get higher yield by planing in direct sunlight this is said to impact flavour and so you'll see shaded varieties available.
Mountain grown and of course plants grown without chemical sprays are desirable.
The critics in the "Black Coffee" documentary, seemed to say with certainty that Ethiopian Yirgacheffe is the best coffee, but of course this is all a matter of taste.
For me, a medium roast Arabica coffee, such as Illy is my favourite. I also like the FairTrade East Timor coffee.
What do you like?
I've just watched parts two and three of a wonderful documentary "