I've been commanded by Lord McDermott to put together a list of great novels by African writers so he'd have some stuff to read. And that's exactly what I've done.
I've intentionally chucked out the books everyone has likely read, such as Things Fall Apart by Chinua Achebe (I know for a fact that Mr. McDermott has read this one, so that's an easy task).
Arrow of God by Chinua Achebe
Ambiguous Adventure by Cheikh Hamidou Kane
Devil on the Cross OR The River Between by Ngugi wa Thiong'o (Matagari is also excellent)
The Famished Road OR Songs of Enchantment by Ben Okri
Waiting for the Barbarians OR The Lives of Animals OR Disgrace OR Foe by J.M. Coetzee
July's People by Nadine Gordimer
Nervous Conditions by Tsitsi Dangarembga
Purple Hibiscus OR Half of a Yellow Sun by Chimamanda Ngozi Adichie
In the Fog of the Seasons' End by Alex La Guma
Houseboy by Ferdinand Oyono
The Dark Child by Camara Laye
One Day I Will Write About This Place by Binyavanga Wainaina (a memoir, not a novel, but oh well)
Bound to Violence by Yambo Ouologuem
Note: I have enormous gaps in my reading knowledge of African writers. You'll notice that there are no writers from places like Egypt, for example, or some of the interior nations. Anyone who would like to suggest novels by writers from these missing countries is encouraged to do so in the comments below!