What current totalitarian governments may be compared to Big Brother (1984)?
I always remember reading Wild Swans, which is a memoir of three generations of Chinese women who experienced massive changes in Chinese society. In it, the author describes how when she first read 1984 she couldn't believe the accuracy with which Orwell had depicted Chinese society under the communist regime. Clearly, China has changed somewhat since then. However, many would argue that we can see elements of an Orwellian society in many other countries and cultures.
You have already mentioned North Korea in your response, but this surely must represent one of the last countries that is committed to isolation to such a radical extent. We might also want to consider some of the Middle Eastern nations that are ruled by something like a dictatorship too. Interestingly, some have argued that the recent phone hacking scandal in Britain with the newspaper called News of the World also represents an Orwellian society where everything we do or say is open to discovery and there is no such thing as privacy. You might want to google this case to read up more about it. There seem to be many situations in today's world that unfortunately show just how topical Orwell's vision of the future is.