Theology books:

On the Incarnation, St. Athanasius

On the Holy Spirit, St. Basil the Great

On the Holy Spirit (letters to Bishop Serapion), St. Athanasius

Five Theological Orations, St. Gregory Nazianzus

Mystical Theology of the Eastern Church, Vladimir Lossky

Orthodox Theology: an Introduction, Vladimir Lossky

In the Image and Likeness, Vladimir Lossky

On the Orthodox Church:

The Orthodox Church, Metr. Kallistos Ware

The Orthodox Way: Metr. Kallistos Ware

Books on the Liturgy/Eucharistic Theology:

The Eucharist, Fr. Alexander Schmemann

Liturgy and Life, Fr. Alexander Schmemann

Baptism, Fr. Alexander Schmemann

Liturgy in Early Christian Egypt, Maxwell Johnson (historical perspective)

Orthodox Spirituality

The Names of Christ, Fr. Matthew the Poor

Orthodox Prayer Life, Fr. Matthew the Poor

The Grain of Wheat, Fr. Matthew the Poor

The Power of the Name, Metr. Kallistos Ware

The Great I AMs of Jesus, Fr. Anthony Coniaris

The Practice of the Presence of God, Brother Lawrence

The Way of the Heart, Henri Nouwen

On the Doctrine of Deification

Achieving your Potential in Christ by Fr. Coniaris (simple read)

Divine Grace by Fr. Tadros Malaty

Stromatas by Clement of Alexandria (available here: http://newadvent.org/fathers/0210.htm)

Homilies on the Gospel of Luke by Origen of Alexandria (especially Homilies 14, 22, 24, 26)

Homilies on the Gospel of John by Origen of Alexandria (especially Book 2)

Homilies on the Epistle to the Romans by Origen of Alexandria (especially Homily 3 and 5)

Commentary on the Gospel of John by St. Cyril of Alexandria; especially see Chapters

Against the Heathen (‘Contra Gentes’) by St. Athanasius of Alexandria (available here: http://newadvent.org/fathers/2801.htm)

On the Incarnation by St. Athanasius (available here: http://newadvent.org/fathers/2802.htm)

Four Discourses Against the Arians by St. Athanasius (especially Discourse 2, available here: http://newadvent.org/fathers/2816.htm)

Five Tomes against Nestorius by St. Cyril of Alexandria (especially Tome 3 and 4, available here: http://www.tertullian.org/fathers/cyril_against_nestorius_03_book3.htm)

Commentary on the Gospel of John by St. Cyril of Alexandria (especially Chapters 2, 3 and 5, available here: http://www.tertullian.org/fathers/)

Commentary on the Gospel of Luke by St. Cyril of Alexandria (esp. Sermon 10, http://www.tertullian.org/fathers/cyril_on_luke_01_sermons_01_11.htm#C10)

Against Julian by St. Cyril of Alexandria (Book 2 especially, available here: http://www.tertullian.org/fathers/cyril_against_julian_02_book2.htm)

Coptic Christology in Practice : incarnation and divine participation in late antique and medieval Egypt by Stephen Davis (Oxford, 2008), especially Chapter  on the Divine Liturgy (academic read)

The Appropriation of Divine Life in Cyril of Alexandria by Daniel Keating (more academic) (Oxford, 2004)

Pauline soteriology in light of deification in Irenaeus and Cyril of Alexandria by Ben Blackwell (Tubingen, 2011) (academic read)

Social Justice

On Social Justice, St. Basil the Great

Women ministry, orders, etc

Women Deaconesses in the Orthodox Church: Call to Holiness and Ministry, Dr. Kyriaki Fitzgerald

The Ministry of Women in the Church, Elisabeth Behr-Sigel

On Relationships, Marriage, Family Life

Love, Sexuality and the Sacrament of Marriage, Fr. John Chryssavgis

(an excerpt from the book: http://www.orthodoxa.org/GB/orthodoxy/society/love.htm)

Marriage and Family Life, St. John Chrysostom

Making God Real in the Orthodox Christian Home, Fr. Anthony Coniaris

Five Love Languages, Gary Chapman

Men are from Mars, Women are from Venus, John Gray