15 Book of Hadith (sunnah.com)

Here’s a short description of the 15 Hadith books on Sunnah.com:

Sahih al-Bukhari – Most authentic Hadith collection; covers all aspects of Islamic life.
Sahih Muslim – Second most authentic; detailed chains of narration.
Sunan Abu Dawood – Focuses on legal rulings and jurisprudence.
Jami` at-Tirmidhi – Includes Hadith classification and scholarly opinions.
Sunan an-Nasa'i – Emphasizes authenticity and legal matters.
Sunan Ibn Majah – Contains unique Hadith, some weak; completes the six major books.
Muwatta Malik – Early legal Hadith from the school of Medina.
Riyad as-Salihin – Thematic Hadith on ethics, manners, and spirituality.
Al-Adab al-Mufrad – Hadith on personal conduct and social behavior.
Bulugh al-Maram – Hadith used in Islamic legal rulings.
Shama'il Muhammadiyah – Descriptions of the Prophet’s appearance and character.
Forty Hadith Nawawi – Core teachings of Islam in 42 concise Hadith.
Usul al-Sunnah – Foundational Hadith on Sunni beliefs.
Al-Arba'in fi Ahwal al-Mawta – Hadith on death and the afterlife.
Al-Lu'lu' wal-Marjan – Only Hadith agreed upon by both Bukhari and Muslim.