Dubai has a huge cigar shop in their duty free area... I bought a lot when travelling through there in Xmas 2014.
Johannesburg airport( OR Tambo) has cigars in their duty free arrivals area ( opposite the baggage carousels) but not a huge selection. The duty free on departures side in OR Tambo, however, is much better... you will need to go into THE BIG, HUGE duty free shop with masses of liquor stocks, perfumes, chocolates etc... just work towards the back area where they sell cigarettes... they have a fair sized walk in humidor with good stocks of Cubans!! I buy there regularly..