We're compiling a list of successful Public Spaces around the world here at the Project for Public Spaces and are particularily interested in any suggestions you all may have to offer.
Of course, what exactly entails success is up for debate but we generally use issues like uses & activities, access & linkage, comfort & image and sociability (read more here).
Personally, I have suggested Zanzibar's Fordani Market as a prime example of a market that is accessible to and includes all people, welcoming many types of social interaction whilst being a safe place due to the Islamic culture of the region.
Africa's successful public places...
The informal bazaar infront of the Great Mosque of Djenne in Mali, West Africa.