I want to share some communion prayers from the Byzantine tradition that I really like. The following is a prayer before communion by St. Basil the Great:
O Lord and Master Jesus Christ, my God, Source of life and immortality, Maker of all things visible and invisible, co-eternal Son of the immortal Father, accept the repentance of me, a sinner. Incline Your ear and hear my prayer: I have sinned, O Lord, I have sinned before Your face, and I am not worthy to lift up my eyes to Your glory. I have provoked Your goodness; I have transgressed Your commandments and disobeyed Your statues. O Lord, be long-suffering with me and show me Your mercy. O You who said through the prophet: "I desire not the death of a sinner, but that he may repent and live", show me Your love and forgive me. Wherefore, even unworthy of heaven and of earth as I am, I despair not of Your salvation. In this life I have wholly yielded myself to sin and have become the slave of the pleasures of this world. I have defiled Your image in me and turned my back on Your loving kindness. When I consider Your infinite compassion, I dare to come back to You, my God and my Maker. Receive me, O Christ, as You received the adulteress; accept me as You accepted the prodigal son, the publican, and the thief on the cross; take away the heavy burden of my sins, O You who take away the sins of the world, You who heal the infirmities of men and give rest to those who are weary and heavy-laden.
Cleanse me, O Lord, from every stain of flesh and spirit; teach me to fulfill Your will in fear and holiness that, having the witness of a pure conscience, I may receive my share of Your holy things and may be united to Your holy body and blood. May I have You to abide in me with the Father and the Holy Spirit. Grant me, until my last breath, to receive the bread and the wine which are Your body and blood, and thereby to receive communion with the Holy Spirit as a provision for the journey to eternal life, and as an acceptable answer at Your dread judgment seat. May I, together with all Your saints, be a partaker of these good things You have prepared for those who love You, O Lord my God. Amen.
Another is from the text of the Divine Liturgy itself and is supposed to be said by all before they go to receive Communion at the priest's bidding, "Approach with fear ...":
I believe, Lord, and profess that You are the Christ, the Son of the Living God, come to this world to save sinners, of whom I am the greatest. I believe also that this is really your spotless body and that this is really your precious blood. Wherefore I pray to You: have mercy on me and pardon my offenses, the deliberate and the indeliberate, those committed in word and in deed, whether knowingly or inadvertently; and count me worthy to share without condemnation your spotless Mysteries, for the remission of sins and for eternal life. Amen.
Yes, that's one of my favorite prayers, together with the second part:
Receive me now, O Son of God, as a participant in your mystical supper: for I will not betray your mystery to your enemies, nor give You a kiss like Judas, but like the thief, I confess You: remember me, Lord, in your kingdom.
Lord, I am not worthy that You should enter under the stained roof of my soul, but as You accepted to be laid down in a cave and a manger for dumb animals, and to enter the house of Simon the Leper, and to receive, when she approached You, the sinful woman who resembled me: deign to enter both into the manger of my senseless soul and into my rubbish-filled body which is (that of a) dead and leprous (man). And as You did not recoil when the filthy mouth of the sinful woman kissed your spotless feet, likewise, my Master and God, do not shun the sinner than I am, but in your goodness and love for mankind grant that I may become a communicant of your all-holy body and blood.
O our God, remit, forgive, excuse my trangressions by which I sinned against You, knowingly or inadvertently, in word or in deed. In your goodness and love for mankind, hold me excused for all of them. Through the prayers of your all-pure and ever-virgin Mother, grant that I may partake without condemnation of your precious and spotless body, for the healing of (my) soul and body. For yours in the kingdom and the power and the glory, for ever and ever.
May the reception of your holy mysteries, Lord, be for me not to judgment or condemnation, but to the healing of (my) soul and body. Amen.