Since buying the complete Collected Works of Melanie Klein would be rather expensive (and not as readily available as this book), this is the next best thing. This one offers all of the very essential Kleinian works, including the Early Stages of the Oedipus Conflict (in which she very daringly challenges Freud's views on the topic, and two papers on manic-depression, which are classics and have still not been equaled even to this day. This book is a great choice for anyone interested in psychology, regardless of their orientation or affiliation.