I still think this is very subjective. Still, some facts may help.
Brazilian Santos is the most commonly used beans in Turkey for Turkish coffee. However, it is not my favorite. Other people may like it a lot. Santos is something like a mixture of many varieties, though its taste may fluctuate a lot with respect to your sources. The main reason that it is used in Turkey is the fact that it is cheap.
Ethiopian Harrar, on the other hand, is one of my favorites. I don't have any concrete proofs but I believe that it was historically one of the beans used for Turkish coffee during Ottoman times, together with Yemen Typica.