The greatest names Allah are in three chapters of the Qur'an: In "Albaqarah", "Ali 'Imran", and in "Taha".

عن أبي أمامة مرفوعا: اسم الله الأعظم في سور من القرآن ثلاث: في "البقرة" و "آل عمرن" و "طه".  الصحيحة: 372. 

In a marfu hadith from Abee Umamah: The greatest names Allah are in three chapters of the Qur'an: In "Albaqarah", "Ali 'Imran", and in "Taha". AsSahih: 372