|A dime a dozen|
The Kutub al-Sittah (the six books) are the primary ahadith collections in Sunni Islam. They consist of Sahih Bukhari, Sahih Muslim, Sunan al-Sughra, Sunan Abu Dawood, Jami al-Tirmidhi and Sunan ibn Majah. The collections total tens of thousands of ahadith.
The first two collections, Sahih Bukhari and Sahih Muslim, are considered the most authentic; the word Sahih itself means "authentic." Authenticity decreases for each collection thereafter, although Islamic maddhabs (schools of religious law or fiqh) have differed on which of the non-Sahih collections are more or less trustworthy.