I purchased Christology and the New Testament by Christopher Tuckett a couple of years ago, but just finally got around to reading it recently.
This book takes a look at the subject of Christology, but from a purely Biblical perspective (no post-apostolic theological development or creedal affirmations are considered). Tuckett, who teaches NT at the University of Oxford, looks at how each NT author presents Jesus, particularly through – but not limited to – their ascription of various titles to Jesus. While Tuckett is liberal in his theological conclusions (and it’s not even clear that he is a confessing Christian), his presentation of the Biblical data is quite good. He has a great way of bringing out the Christological emphasis of the different NT authors/books.
If you are looking for a good introduction to NT Biblical Christology, this is a good resource.