Here is a list of every "country," dependent area, and disputed territory (according to colonial boundaries) in the world to see how many of these you can tick off. The only "country" I excluded was Vatican City for obvious reasons. The only rule is that you can't count colonial classics as being from that country (for example, Albert Camus doesn't count for Alergia, and Joseph Conrad doesn't count for Congo). The way I'm selecting my books is that the author has to have been born in said country, and the book should preferably centre on themes related to that country and its history.
Have fun!