Via Infosthetics, the above graph (culled from the Flash visualization here):
...maps the base pay of the world's parliamentarians, ranked by country and expressed as a multiple of per capita GDP, versus a "Good Governance Index", which itself is a combination of the Democracy Index, the UN's Human Development Index and the Perception of Corruption Index.
In short, the further away the country dot is removed from the yellow cross, the more their MPs are being paid. The larger the (counter-clockwise) angle from the yellow line, the worse their corresponding governance.
Some commenters on the Infosthetics post have decried the visualization as unnecessarily flashy, but I think it's actually pretty useful, at least for relative comparisons. The best cluster of countries in this analysis are all countries with small, fairly homogenous populations such as Switzerland, Iceland, Luxembourg, etc. Not all such countries are in the same cluster (notably Austria and Belgium), but the biggest country (population wise) in the best cluster is Canada, with about 33 million people.
The second-best cluster of countries includes much larger countries, including the US, the UK, France, Germany, Spain, and Japan (Japan is the line that extends to the right out of the image). In general, these countries are more also more diverse (namely the US, the UK, and France).
So, in general, the trend seems to be that smaller, more ethnically homogenous countries get more for their money than large, ethnically diverse countries. This isn't all that surprising. But what was a little surprising for me was how relatively well the US does, considering that it is both the largest country in the upper-right quadrant and also the most diverse. Of course, it should be reiterated that the US' position on the graph is likely heavily influenced by the fact that the base pay is normalized per GDP, and the US' GDP is quite a bit higher than some of the countries in its cluster.