One Time, Kulula, Mango
American Airlines has very inexpensive flights to Africa. Delta also is known for it's low cost service to Africa.
The companies that offer cheap flights to South Africa are SouthWest Airlines and United States Continental Airlines. Thes two companies have great reviews.
South Africa's low-cost airline is known as 1time Airline. Founded February 25, 2004 and based in Kempton Park, Ekurhuleni, Gauteng, operates scheduled domestic and regional flights.
The companies that offer cheap flights to Namibia include Orbitz that is the premier industry leader in discounted flights. The cheap flights to Namibia which is located in Africa is advertised extensively on the Orbitz websites as well as on billboards nationwide.
There are no direct flights between Johannesburg and Beijing. The quickest flight is some 19 hours with Cathay Pacific Airline: http://www.southafrica.to/transport/Airlines/to-South-Africa/flights-to-Johannesburg/flights-Beijing-to-Johannesburg.php5
There are no known direct flights from Auckland to Johannesburg OR Tambo International, nor are there any direct flights to Johannesburg Lanseria International. Thus, accurate flight durations may only be obtained from airline companies who will use transit stops before heading to Johannesburg.
www.expedia.com and www.orbitz.com will both help you find the cheapest flight to Africa from the US. As flight costs change constantly, there is no one cheapest carrier.
Many airlines fly from Africa to the Caribbeans. British Airways and Iberia offer two-leg flights, where you first fly from Africa to a European hub (e.g. London Heathrow), and then to the Caribbeans (say Kingston, Jamaica). An alternative is to get from Africa to a United States airport (flights via many airlines) and then go with Air Jamaica to the Caribbeans. Please see the related links for details.
El Al is the national airline of Israel. It operates regular international passenger and cargo flights between its hub at Ben Gurion International Airport and destinations in Africa, Asia, Europe, and North America, as well as domestic connections to Eilat.
The price of south African airways to go to Africa is considered average in comparison to other airline flights. It could be cheaper but consider that for a flight all the way to Africa, which will take hours should be at least partway comfortable.
Europe
Ethiopian Airlines is the largest airline in Africa by fleet size, number of destinations, and revenue. It is known for its extensive network covering Africa and international routes.