Emotion, Reason, and the Human Brain Antonio Damasio
This is a pretty good book, much better written than Looking for Spinoza or The Feeling of What Happens. It has basically all of the major good ideas present in the later books, and is much better edited. The only thing the later books really add is new evidence in support of the early ideas. Read this and skip the others, however I read the others first, and my discussion of his ideas is in those reviews.