1. Siddharth Kara, Sex Trafficking: Inside the Business of Modern Slavery. A serious research effort and the best book so far on its topic.
2. Joseph Contreras, In the Shadow of the Giant: The Americanization of Modern Mexico. A neglected side of recent Mexican history; one of the best books on where Mexico is headed. Here is a recent article on related progress in Mexico's legal system.
3. Mahmood Mamdani, Saviors and Survivors: Darfur, Politics, and the War on Terror. This revisionist account argues the conflict is political rather than racial and that the notion of "genocide" is an externally imposed category for international political reasons. I found the arguments of this book hard to assess but it made for stimulating reading.
4. George Scialabba, What are Intellectuals Good For?, recommendation via Henry. Fascinating essays on 20th century intellectuals, from an "ethical left" point of view. I especially liked the piece on Pasolini (a favorite director of mine).
5. Dying Inside, by Robert Silverberg. This 1972 classic has just been republished. Is it science fiction or speculative fiction? In any case it is full of social science; the basic premise is about how other people react to a man who has the ability to read peoples' minds and how psychologically destructive this power turns out to be. If you wish to read every great science fiction book this is a must.