There are many evil deeds, but some are even worse. They are mentioned as follows in hadith-i sharifs:

(The worst of people is the one who is avoided due to fear for his harm.) [Bukhari]

(The worst of people is the one whose life is long but whose deeds are evil.) [Tirmidhi]

(The worst of people is the one who is double-faced.) [Bukhari]

(The worst of people is the one who becomes angry very easily but who calms down in a very long time.) [Tirmidhi]

(The worst of people is the one who causes humans harm and who offends them.) [the book İslam Ahlakı]

(The worst of people is corrupt scholars.) [Bazzar]

(The worst of people is the one who restricts the sustenance of his family, though he has the means to provide.) [Tabarani]

(The worst idiocy is to abandon the Islamic religion and to incline to another religion.) [Daylami]

(The worst of deeds is bid’ah.) [Bukhari, Muslim, Nasai]

(The worst of creatures is exponents of bid’ah.) [Abu Nu’aym]

(The worst disease is stinginess.) [Dara Qutni]

(The worst meal is the feast where wealthy ones are invited while poor ones are not.) [Bukhari]

(The worst thief is the one who steals from his own salat. He steals from ruku’ and sajda.) [Tabarani]

(The worst remorse is that which is felt on the Day of Judgment.) [Bayhaqi]

(The worst of the old is the one who tries to be like the young in negligence [ghaflah] and in obeying the nafs.) [Tabarani]

(The worst quality is stinginess and extreme cowardice.) [Bukhari]