Mashabane Rose Architects is well known in their home in South Africa as well as abroad, but I have just been exposed to their work. Not only do they develop intriguing modern designs, but most of their work (including HIV/AIDS care facilities, memorials, and Oprah's new girls' school) also has a social conscience. They are quite a spectacular group of architects... and people.
University of Johannesburg Art Centre
The two photos above are the result of a winning entry for an October 2003 competition. Mashebane Rose provide this lovely design for the newly merged Johannesburg Technikon and RAU University contemporary theatre and art gallery. 
Hector Pieterson Memorial
The two photos above are of the Hector Pieterson Memorial museum in Soweto. It is dedicated to the youth uprising against apartheid in 1976 and named after 12 year old Hector, who was the first student killed in the conflict. 