The very important Epistle to the Romans. This is a set of devotions based on key passages in Paul's thorough explanation of the most essential and important doctrines in the New Testament. 

There is so much comfort in the Psalms and wisdom in the Proverbs that it's a book we ought to be reading on a regular basis. The books of kings and prophets, their laments and thanksgiving. 

The Synoptic Gospels, Matthew, Mark and Luke, all preaching the same message of love in similar but distinct ways plus the Good News of John that just stands on its own.