The bible is perfect, and every other book has holes. With that said, there are many books that will add a great deal to your life as a follower of Jesus. The list below is not an exhaustive one, but it is a good start.
Scroll over the image for a link to purchase the book.
ESV Study Bible
Gospel Transformation Bible
Solid joys daily devotional (Mobile App)
Morning and evening devotional book
Morning and evening devotional (Online version)
Morning and evening devotional (Mobile App for Mac)
Morning and evening devotional (Mobile App for Android)
The pursuit of holiness
The pursuit of God
The Gospel Story Bible
Long Story Short Family Devotions
Old Story New Family Devotions
The Jesus Storybook Bible
THE GOSPEL AND THE CHRISTIAN LIFE:
The gospel centered life
The cross centered life
The explicit gospel
What is the gospel?
The reason for God
Systematic Theology: An introduction to biblical doctrine
Systematic Theology: An introduction to Christian belief
Christian beliefs: 20 beliefs every Christian should know
Doctrine: What Christians should believe
Practical theology for women
The church: The gospel made visible
What is a healthy church?
What is a healthy church member?
Creature of the Word: The Jesus-centered church
MISSION AND MISSIONS:
Multiply: Disciples making disciples
Be the church
For the city: Proclaiming and living out the gospel
Let the nations be glad
MARRIAGE AND FAMILY:
The meaning of marriage
When sinners say “I do.”
What did you expect? Redeeming the realities of marriage
Recovering biblical manhood and womanhood
The exemplary husband
Manhood restored: How the gospel makes men whole
Shepherding a child’s heart
Money, possessions and eternity
Whose money is it anyway?
The total money makeover