Of the African nations, which ones (top 3) have the longest & most stable economy?

South Africa has a good contemporary-art market. Stable governments? Morocco, I think.
Other African nations with both? For that combination you need a lot of rich people living in a place and a lot of rich people interested in visiting. Egypt, maybe. Uganda?
Nigeria? Kenya? Big cities, big banks, big societies….. Interested in what other people come up with.

Senegal

I’d definitely imagine Egypt and South Africa to be on the Top Three… a little wikipedia research showed me that South Africa, Nigeria and Algeria have the highest GDP (a market value ranking)... that doesn’t necessarily show “stability” but I’m sure it reflects it at least slightly…