This particular talk, by Dr. Richard Wilkinson, is a fairly devastating indictment of the negative impacts of social inequality. One might argue that the presentation is biased, it would depend on the data set you looked at, data can be made to say anything, etc ... but if you watch this talk with an open mind and no predispositions, I struggle to see how anyone could see social inequality as a force for evil in our modern society.
Also, it was weird to watch something where the USA is consistently worse than almost everyone else ... I am used to the US being number one, at least in my own head (although around the world I think we are beginning to realize this is just not the case anymore for so many things). But as a scientist, to see it laid out so plainly and effectively was actually pretty tough.
Anyway, watch the talk, the video is below - it is definitely worth 17 minutes of your lives. In case you cannot see the video, the link is here http://www.hulu.com/watch/292664/tedtalks-richard-wilkinson-how-economic-inequality-harms-societies.