If you are looking for a good prayer book, which contains solid confessional prayers (meaning that they focus on the true source of justification, namely the crucifixion of our Lord) and point to the source of true hope and peace (namely the providential care of our Lord through Word and Sacrament,) then I recommend you purchase "Meditations on Divine Mercy," written by Johann Gerhard; translated by President Matthew C. Harrison. You can find it at CPH.org or Amazon.com; ISBN 0-7586-0387-8.
I have not really been drawn to a prayer book until I began reading through Gerhard's prayers. It seemed that all the one's I had been reading were written by me. Gerhard does a great job bringing out the sinfulness of man, in light of the Scripture, and pointing to the source of forgiveness. He breaks the "7 rules that every Christian ought to break as often as possible" (another great book; Broken written by Rev. Jonathan Fisk, again CPH.org or Amazon.com) and points you to Word and Sacrament where our Lord is truly present to forgive the sins of his people.
One prayer in particular that I have come to love is titled "Prayer For the Mortification of the Old Man":
O HOLY AND MOST MERCIFUL GOD, Father of our Lord Jesus Christ, I beg You in the Holy Spirit, for the sake of Your Son, to powerfully work in me and put to death the old man. I need this every day so I can be made strong in You according to the inner man. Sin dwells in my flesh (Romans 7:17). Give me the strength of the Spirit so I will not allow sin to rule me (Romans 6:12). You set my hidden sins in the light of Your countenance (Psalm 90:8). I ask You to bring them to light in my heart so I may recognize them, regret them, and humbly seek their forgiveness.
I am not yet completely free from the indwelling of sin. Please be gracious, I ask, and grant me freedom from the guilt and condemnation of sin. The law of sin in my members is warring against the law of my renewed mind (Romans 7:23). Give me the grace of Your Spirit so I may take captive the law of sin and not be captive to the old law of the flesh. The flesh lusts against the Spirit, and the Spirit against the flesh (Galatians 5:17). Indeed, the spirit is willing, but the flesh is weak (Matthew 26:41). Give my spirit, therefore, great power and strength so it may overcome the depraved lusts that battle in my flesh. Strengthen my inner man by Your Spirit (Ephesians 3:16) so lust cannot break the inner man's power. How incredibly difficult and hard it is to fight against one's self. When I fight the flesh, I am fighting myself. How difficult and arduous it is to remove an enemy from one's own home.
Unless You clothe me with heavenly strength in this war, I am afraid that I will certainly be defeated by the hidden plots of the enemy. Strike down, burn, cut, and kill the old man so I can flee from this flattering fraud and seduction. Grant that daily I die to myself so the lures of the flesh will not draw me away from the true life that is in Christ. Inflame the fire of the Spirit in my heart so I may offer to You as a sacrifice the beloved child of my soul, which are depraved lusts and my own will. Flesh and blood cannot receive the inheritance of the kingdom of God (1Corinthians 15:50). May they die in me so I will not be excluded from the kingdom of heaven. Those who live according to the flesh will die; those who by the Spirit kill the deeds of the flesh will live (Romans 8:13). Those who belong to Christ crucify the flesh with its desires (Galatians 5:24). Pierce and crucify my flesh, O Christ, You who were pierced and crucified on the altar of the cross for me. AMEN.
This is a preview of the excellent quality of Gerhard's meditations on divine mercy. This prayer seems to reflect on Luther's explanation of the third petition of the Lord's Prayer. "Thy will be done on earth as it is in heaven. What does this mean? Answer: The good and gracious will of God is done indeed without our prayer. But we pray in this petition that it may be done among us also. How is this done? Answer: When God BREAKS and HINDERS every evil counsel and will that would not let us hallow the name of God nor let His kingdom come, such as the will of the devil, the world, AND OUR FLESH."
This is essentially Gerhard's request, that the evil intentions of his own flesh be mortified by our Lord through the death and resurrection of Christ, which also echoes Galatians 2:20 "I have been crucified with Christ. It is no longer I who live, but Christ who lives in me." It is a strange paradox that our Lord brings us to life through death. This ultimately happens through baptism where we die to sin and are connected to the death and burial of Christ, but even more to his resurrection to everlasting life (Romans 6:2-4). God bless in the merits of Christ crucified, for you.
In the name of the Father and of the Son and of the Holy Ghost. Amen.