I have to go with Tevinter. As evil as much of the culture is (and it surely is), there is room for change and for growth. You can at least make the case in Tevinter that things are wrong and need to be changed without being regarded as a dangerous loon to be "re-educated". In fact (or so we're told) there is a significant (if outgunned) reform movement in Tevinter, and not all magisters eat children or drink their blood (just most of them).
Basically it comes down to this: Tevinter is the way it is for a lot of reasons, but it has the ability (at least in principle ) to understand what is wrong and THAT is the first essential step to making things better.
The Qun is perfect and has all the answers. Just ask them. Don't worry about the re-educators. They are there to "help you".....in a 1984 sort of way. In such a society, constructive change is essentially impossible.