It is really hard to pick one, and to do so, you have to look at a few factors. If we consider the African team that has won the most African Cup of Nations, then that is Egypt, they have won it 7 times, if we consider the African team that has gone furthest in a World Cup, then that is Morocco, who reached the Semi-Final of the last World Cup, if we consider the African country with the strongest club league, then it is definitely the Egyptian league.

That said, if i am to pick a country, i'd say Egypt, based on what they have achieved, winning the AFCON so many times, and they also have successful football clubs like Al Ahly and Zamalek

It should definitely be Nigeria. The Super Eagles might not be at their best now, but Nigeria has the highest number of professional players in Africa. If you take a headcount of African players who play abroad, you might ascertain that Nigeria has the highest population.  Maybe the high population of the country contributed to this fact. Just like Brazil, Nigeria can boast of more football talent in Africa.

Another indicator of a football nation is the popularity of the sport at the grassroots. Football is the most popular sport in Nigeria and it is played by children in almost all the nooks and crannies of the country.