The Cost of Discipleship, Dietrich Bonhoeffer
A New Testament Biblical Theology, G.K. Beale
The Chief Theological Topics (1559), Philip Melancthon - trans. by J.A.O. Preus
Encountering the Mystery, Ecumenical Patriarch Bartholomew
Jesus of Nazareth & Jesus of Nazareth: The Infancy Narratives, Pope Benedict XVI
The Way to Nicaea & The Nicene Faith 1 and 2, John Behr
The First Thousand Years, Robert Louis Wilken
Turning Points, Mark Noll
The Division of Christendom, Hans Hillerbrand
The Church in History, John E. Booty
The Church, the Falling Away, and the Restoration, J.W. Shepherd
Theological Roots of Pentecostalism, Donald W. Dayton
Religious Literacy & God is Not One, Stephen Prothero
The Mosaic of Christian Belief, Roger E. Olson
The Church Defended, Richard Hooker
I have many others but this is the best of my collection close at hand. 2/3 of my books are in storage at my parents' house. One day I will be able to drive out and get them but not anytime soon. Interestingly, most of these are books I acquired myself - there are only a couple that were required texts for coursework I've done.