Answer:
(Fatwa 335=306/N)
You did not mention what are the criteria of being the best to you? Therefore, it is difficult to regard any book as the best. However, Siratul Mustafa, Rahmatul Lilalameen and Alrahiqul Makhtoom are among better and well-known books of Sirat. Siratul Mustafa is easier and suitable for you to study.
Allah (Subhana Wa Ta’ala) knows Best
Darul Ifta,
Darul Uloom Deoband
