Ayat-ul-Kursi
اللَّهُ لَا إِلَهَ إِلَّا هُوَ الْحَيُّ الْقَيُّومُ لَا تَأْخُذُهُ سِنَةٌ وَلَا نَوْمٌ لَهُ مَا فِي السَّمَاوَاتِ وَمَا فِي الْأَرْضِ...
Transliteration
Allahu la ilaha illahu huwal-Hayyul-Qayyum...
Translation
Allah - there is no deity except Him, the Ever-Living, the Sustainer of existence. Neither drowsiness overtakes Him nor sleep. To Him belongs whatever is in the heavens and whatever is on the earth...
Benefits
Protection, salvation, and guidance. Reciting it before sleep protects from shaytan and brings peace.