Alive in Joburg is a masterfully executed short science fiction film in the style of a documentary, about a minority group of aliens who are stranded in the shantytowns of Apartheid-era (post-Apartheid? The alternate timeline is vague) South Africa. The aliens are a kind of racial minority in a race-charged society, and present a contradictory blend of great power and helplessness. The film blends in CGI, costumes, even what I think is stock footage, without any noticeable seams. It's a really compelling glimpse into an sf world, just the sort of thing that short sf films do best when they're well-made.
(Thanks, Craniac!)
Update: Ben points us to TempBot, another great movie from the same guy. There's also a fantastic showreel.
Update 2 Christopher sends us a link to the Alive in Joburg film on the Internet Archive.