In Za'ad al Ma'ad by Hazrat Imam Ibn Qayyim (ra), he has described many prayers. I am bad at typing in Arabic, so please bear with me in writing this out in English letters for the du'as he mentioned that the Holy Prophet Muhammad (saw) would say:
"Subhanakallahumma Rabbana Wa Bihamdika, Allahummaghfir Lee"
"O Allah, our Lord glory and praise be to You. Oh, Allah! Forgive me."
"Subbuhun Quddusun, Rabbul-Mala'ikati War-Ruh"
"Most Glorified, Most Holy, Lord of the angels and the Spirit [i.e. Gabriel]."
"Allahumma Laka Sajadtu Wa Bika Aamantu Wa Laka Aslamtu, Sajada Wajhee Lilladhee Khalaqahu wa Sawwarahu Wa Shaqqa Sam'ahu Wa Basarahu, Tabarakallahu Ahsanul-Khaliqeen"
"Oh, Allah! For You I have prostrated, in You I have believed, to You I have submitted. My face has prostrated for the One Who created it and shaped it, then brought forth its hearing and sight: Blessed be Allah, the Best of Creators."
"Allahummaghfir Lee Dhanbee Kullahu, Diqqahu wa Jallahu Wa Awwalahu Wa Aakhirahu Wa Alaniyatahu Wa Sirrahu"
"Oh, Allah! Forgive me all my sins; the minor and the major, the first and the last, the apparent and the hidden."
"Allahummaghfir Lee Khatayaya Wa Jahlee Wa Israfee Fee Amree Wa Ma Anta A'lamu Bihi minee, Allahummaghfir Lee Jiddee wa Hazlee Wa Khatayaya Wa 'Amdee Wa Kullu Dhalika 'Indee. Allahummaghfir Lee ma Qaddamtu wa ma akhkhartu wa ma Asrartu wa ma a'lantu anta ilahee la ilaha illa anta."
"Oh, Allah! Forgive me my mistakes and my ignorance and my extravagance, for You know them better than I. Oh, Allah! Forgive me my serious mistakes and those made in jest my (unintentional) and my intentional mistakes and all of these are in me. Oh, Allah! Forgive me my sins in the past and in the future, and those which I concealed and those which I committed openly. You are my Ilah and none has the right to be worshiped except You."
You can download the PDF of this book. It is an abridged version though. But this is from that version. It is on pp. 17-18 of the downloadable pdf from online. That is, "Zad al Ma'ad" by Ibn Qayyim.