The "Treasury of Daily Prayer" is not just your average devotional book. This Lutheran resource brings together scripture readings, prayers, psalms, hymns, and devotional readings from the church fathers to guide daily prayer and meditation on God's Word. It is also designed around the church calender.
I got a copy of "Treasury of Daily Prayer" for my wife while I was gone for training for my job. Together we take turns doing the readings before we crash for the evening. Each day has a Psalm (with suggested further Psalm reading) Old Testament reading, New Testament reading, a writing from one of the church fathers that paralells the reading, a hymn, suggested reading from "Concordia: The Lutheran Confessions" (a reader's edition of the Book of Concord) and a prayer. It even has built in liturgy. If you're not used to liturgy (we attend a confessional Lutheran church that does not use traditional liturgy) you can easily adapt things to meet your likes and needs.
What I really like about "Treasury of Daily Prayer" is that it enables me to see to the spiritual needs of my wife and I by spending time in the Scriptures and time further deepening our understanding of theology at the same time.