Ethical Consumer magazine is revising how they assess whether a country's regime is oppressive (issue EC98). This is then used to flag corporations that support these regimes so that you can avoid buying from them. The list criteria is still being revised but Sudan, China and Burma are proposed as the most oppressive regimes. Of course it's pretty hard to avoid buying stuff made in China.
Countries are ranked on occurences of 8 criteria. Turns out the the US scored 4 because of prisoners of conscience, torture, disappearances and the death penalty so it now makes it on the oppressive regime list.