Outside of the Holy Bible, and catechetic resources:
- The Mystical City of God, Four Volumes, by Venerable Mary of Agreda (TAN Books) Perhaps my favorite writing next to the Bible.
- Raised from the Dead, by Fr. Albert J. Hebert, S.M. (TAN Books)
- Purgatory – Explained by the Lives and Legends of the Saints, by Fr. F.X. Shouppe, S.J. (TAN Books)
- The Autobiography of a Hunted Priest, by John Gerard (Image Books)
- The Sinner’s Guide, by Venerable Louis of Granada (TAN Books)
- Sermons of St. Alphonsus Liguori (TAN Books)
- Butler’s Lives of the Saints
- Anything written by Fr. Michael Muller, C.S.S.R.
- Anything written by Fr. Martin von Cochem, O.S.F.C
- The Divine Comedy, by Dante (http://www.poetryintranslation.com/PITBR/Italian/Danthome.htm )
Leave comment if you would like to add to this list as your favorite books. Many more books could be added!
I would like to make a special reference to the book written by St. Ignatius of Loyola, Spiritual Exercises. I believe St. Ignatius is one of the greatest men to ever have lived. His book reflects his greatness. The Spiritual Exercises is a spiritual classic from a spiritual giant.
Speray's Catholicism in a Nutshell 
Just adding 4 books that were really helpful to me that could be added to the fine list here of which I have read most of them. You might add your own from your own reading experiences:
1. “SPIRITUAL COMBAT” by Dom Lorenzo Scupoli ===> http://catholic-lifetime-reading-plan.blogspot.com/2008/08/spiritual-combat-by-fr-dom-lorenzo.html
2. “THE 12 STEPS TO HOLINESS AND SALVATION” by St. Alphonsus Liguori ===> http://www.amazon.com/The-Twelve-Steps-Holiness-Salvation/dp/0895552981
3. “AN INTRODUCTION TO THE DEVOUT LIFE” by St. Francis De Sales ===> http://www.amazon.com/Introduction-Devout-Life-Francis-Sales/dp/0375725628/ref=sr_1_1?s=books&ie=UTF8&qid=1339637095&sr=1-1&keywords=Introduction+to+the+devout+life
4. “THE IMITATION OF CHRIST” by Thomas Kempis ===> http://www.amazon.com/Imitation-Christ-Dover-Thrift-Editions/dp/0486431851/ref=sr_1_1?s=books&ie=UTF8&qid=1339637235&sr=1-1&keywords=the+imitation+of+Christ+by+thomas+kempis
[NOTE: Pope Pius XII loved this last one so much that it was reported that he kept it by his night stand.]
St. Louis de Montfort’s writings ranked up there somewhere, especially Secret of the Rosary.
Rama Coomeraswamy’s “The Destruction of Christian Tradition” is a good book to help people hold the position of sedevacantistism along with “New Montinian Church” by Joaquin Saenz y Arriaga. These along with yours cover every angle and if more people looked into the facts and quit making excuses there might be more truly Catholic people in this world but unfortunately its becoming fewer.
1. The Life of Mary by the Mystics – Compiled by Raphael Brown
2. Eucharistic Miracles – Joan Carroll Cruz
3. Any books written by Joan Carroll Cruz
4. Any books written by Anne Catherine Emmerich or other approved Mystics
5. Raised from the Dead – Fr. Albert J. Herbert
6.The Destruction of Christian Tradition – Rama Coomeraswamy’s
7. The Popes against Modern Errors – TAN publiction
8. Catechism of St. Pius the X
9. The Facts about Martin Luther – Msgr. Patrick F. O’Hare
10. many books