Pronunciation: Allahumma anta rabbi laaa ilaaha illa anta. Khalaq tani wa aana a'bduk. Wa aana aa-la ahdika wa wa'di-ka masta-ta'tu. Aa u'zubika min-sharimaa sa-na'tu. Aa-bu u-laka bi-ni'matika a'laiya. Wa aa-bu u-bi-zambi Fagh-firli Fa-inna-hu la yagh-firuz-zu-nu ba il-la anta.
Meaning: O Allah, You are my Lord, none has the right to be worshipped except You, You created me and I am Your servant, and I abide to Your covenant and promise [to honour it] as best I can, I take refuge in You from the evil of which I committed, I acknowledge Your favour upon me and I acknowledge my sin, so forgive me, for verily none can forgive sins except You.
Virtue: The Prophet (ﷺ) said, "The best supplication for seeking forgiveness is (Syed-ul-Istighfar)".
If somebody recites it during the day with firm faith in it and dies on the same day before the evening, they will be from the people of Paradise and if somebody recites it at night with firm faith in it and dies before the morning they will be from the people of Paradise.
Reference: Sahih Al-Bukhari, Volume 8, Book 75 #318