ENOfficial
Anas said that the Prophet's most frequent supplication was, "O God, bring us blessing in this world, blessing in the next, and guard us from the punishment of hell." (Bukhari and Muslim.)
Source: sunnah.com
Other translations
Arabic
وَعَن أنسٍ قَالَ: كَانَ أَكْثَرُ دُعَاءِ النَّبِيِّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ «اللَّهُمَّ آتِنَا فِي الدُّنْيَا حَسَنَةً وَفِي الْآخِرَةِ حَسَنَةً وقنا عَذَاب النَّار»
sunnah.com