The Benevolent Dictator. Many people have tried that route, but the thing is, there must be a moral foundation, and strength of character, to carry this out. Most despots have neither, or at best, only one.
The ability to chop up your tribe's rivals without a second thought does not bode well for a form of government in which all, at least under the law, are equals.
Consider if you would, the environment.
Sub-Saharan Africa is a savage, brutal region. This gives rise to brutal cultures, with brutal rules of conduct. The Near East was the same, but look at what happened: empire after empire rose and fell, all recognizing that you didn't put the entire population to the sword, or reduce the cities and farms to ash, after each conquest. Local populace was assimilated into the conquerors. Cities were repaired, and redressed to the masters. Trade was restored, if it even died during the conflict.
Many of the Northern Eurpoean wars all revolved around the seasons - not because of weather, but because of the harvest. The peasants who were conscripted into the armies had to be released to get the crops in. This was an unspoken rule of war back then, because of the harvest failed, the ruling class would starve as well.
I would agree with this point: Africa has yet to evolve as a "culture"; even though the Euro-Eastern cultures have seen exposure, it hasn't taken root yet - I'll leave it to the next commentor to continue....
Yes. The idea has its limitations, the first of which being that I am approaching this from the viewpoint of a person with morals. I doubt the usual suspects who run most African countries have a moral core, ergo, the Benevolent Dictator scheme won't work.
However, I am willing to take offers from African countries to test out the theory. I swear I'll only take 10%.