Classical
Ahmad Ibn Hanbal
Ibn Battah
Ibn Qudama Al Maqdisi
Ibn Rajab Al Hanbali
Imam Muslim
Imam Al Shafi’i
Imam Abu Hanifa
Imam Malik
Abdullah Ibn Ahmed Ibn Hanbal
Ibn Majah
Imam Bukhari
Imam Abu Dawud
Imam Tabari
Hassan Al Basri
Imam Mujahid
Sufyan al-Thawri
Imam al-Barbahari
Not for beginners / Most books only in Arabic / Should be studied with a shaykh's assistance and with thorough commentaries
Ibn hazm
Imam Ghazali
Imam Nawawi
Imam ibn hajar al askalani
Senior Scholars
Muhammad Ibn Abdul Wahhab and his children
(Sulayman Ibn Abdul Wahhab, etc…)
Ibn Taymiyyah
Ibn Kathir
Ibn Al Qayim Jawziya
Ibn Rajab
Ibn Masud Al Baghawi