As part of the daily after Fajr program regarding the life of a Muslim, the following is a Sunnah Dua that is the loftiest of all repentance.

Shaddad bin Aus (R.A) narrates that Rasulullah صلى الله عليه وآله وسلم states that Sayyidul Istighfar (the most loftiest of all types of repentance), is that a servant says the following once:

اللَّهُمَّ أَنْتَ رَبِّي لّا إِلَهَ إِلَّا أَنْت،خَلَقْتَنِي وَأَنَا عَبْدُكَ،وَأَنَا عَلَى عَهْدِكَ وَوَعْدِكَ مَا اسْتَطَعْت،أَعُوذُ بِكَ مِنْ شَرِّ مَا صَنَعْت،

أَبُوءُ لَكَ بِنِعْمَتِكَعَلَيَّ، وَأَبُوءُ بِذَنْبِي فَاغْفِر لِي فَإِنَّهُ لَا يَغْفِرُالذُّنُوبَ إِلَّا أَنْتَ

Translation:  O Allah! You are my Lord. There is no God besides You, You created me, I am Your slave and with all my strength, I remain steadfast to Your promise and I beseech You to forgive me any evil I may perform. I humbly affirm what You bestow upon me and I plead guilty to my sins. Forgive me. For besides You there is none to forgive me.