This one is impossible. Why? So many books on Jesus have been truly ground-breaking and paradigm-challenging, and I’ve limited myself to ten. This list is the top ten Jesus books that I like to read and from which I have learned so much. I don’t agree with any of them completely. Some of these are no longer in print, but can be found (often, usually) on Advanced Book Exchange.
1. N.T. Wright, Jesus and the Victory of God
2. B.F. Meyer, The Aims of Jesus (long philosophical intro)
3. J. Jeremias, New Testament Theology. Vol. 1: The Proclamation of Jesus
4. C.H. Dodd, The Founder of Christianity
5. J.D.G. Dunn, Jesus Remembered
6. G.B. Caird, New Testament Theology, chp. 9.
7. G. Vermes, Jesus the Jew
8. H.J. Cadbury, The Peril of Modernizing Jesus
9. B. Wiebe, Messianic Ethics
10. D. Kraybill, The Upside-Down Kingdom
Sure, there are many more, especially if you want to look at this from seminal studies for the academic study of Jesus (Johannes Weiss, Albert Schweitzer, R. Bultmann, G. Bornkamm, W. Manson, T.W. Manson, H.J. Cadoux, M. Dibelius, R. Schnackenburg, L. Goppelt, E.P. Sanders, R.A. Horsley, J.P. Meier, M. Borg, J.P. Meier, B.D. Chilton, J.D. Crossan, E.S. Fiorenza, and on and on). But, this list is my list of the best books to read about Jesus, and they are not all that repetitive amongst themselves.
By the way, Jimmy Dunn and I are co-editors of an anthology of Jesus studies coming out this fall from Eisenbraun’s. It collects seminal essays or chapters in the unfolding history of how scholars have understood Jesus.