Rather than one title, the Qur'an names Allah by many qualities: the Most Merciful, the Source of Peace, the Creator. These three verses gather more of them in one place than almost anywhere else, and call them 'the most beautiful names'.
Al-Hashr 59:22–24
Listen on Quran.comهُوَ ٱللَّهُ ٱلَّذِى لَآ إِلَـٰهَ إِلَّا هُوَ ۖ عَـٰلِمُ ٱلْغَيْبِ وَٱلشَّهَـٰدَةِ ۖ هُوَ ٱلرَّحْمَـٰنُ ٱلرَّحِيمُ
59:22He is Allah, besides whom there is no god, the Knower of the unseen and the seen. He is All-Merciful, Very-Merciful.
هُوَ ٱللَّهُ ٱلَّذِى لَآ إِلَـٰهَ إِلَّا هُوَ ٱلْمَلِكُ ٱلْقُدُّوسُ ٱلسَّلَـٰمُ ٱلْمُؤْمِنُ ٱلْمُهَيْمِنُ ٱلْعَزِيزُ ٱلْجَبَّارُ ٱلْمُتَكَبِّرُ ۚ سُبْحَـٰنَ ٱللَّهِ عَمَّا يُشْرِكُونَ
59:23He is Allah, besides whom there is no god, the Sovereign, the Supreme-In-Holiness, the Safe (from all defects), the Giver-Of-Peace, the Guardian, the All-Mighty, the All-Repairer, the Sublime. Pure is Allah from what they associate with Him.
هُوَ ٱللَّهُ ٱلْخَـٰلِقُ ٱلْبَارِئُ ٱلْمُصَوِّرُ ۖ لَهُ ٱلْأَسْمَآءُ ٱلْحُسْنَىٰ ۚ يُسَبِّحُ لَهُۥ مَا فِى ٱلسَّمَـٰوَٰتِ وَٱلْأَرْضِ ۖ وَهُوَ ٱلْعَزِيزُ ٱلْحَكِيمُ
59:24He is Allah, the Creator, the Inventor, the Shaper. His are the Most Beautiful Names. His purity is proclaimed by all that is in the heavens and the earth, and He is the All-Mighty, the All-Wise.
English translation: Mufti Muhammad Taqi Usmani, The Meanings of the Noble Qur'an, via Quran.com. Arabic: Uthmani script.
Which of these names would you most want to be true?