Partial list from: Wikipedia
- Pope Stephen VI (896-897), who had his predecessor Pope Formosus exhumed, tried, de-fingered, briefly reburied, and thrown in the Tiber
- Pope John XII (937-964), who gave land to a mistress, murdered several people, and was killed by a man who caught him in bed with his wife.
- Pope Benedict IX (1032-1044,1045,1047-1048), who “sold” the Papacy
- Pope Boniface VIII (1294-1303), who is lampooned in Dante‘s Divine Comedy
- Pope Urban VI (1378-1389), who complained that he did not hear enough screaming when Cardinals who had conspired against him were tortured.
- Pope Alexander VI (1492-1503), a Borgia, who was guilty of nepotism and whose unattended corpse swelled until it could barely fit in a coffin.
- Pope Leo X (1513-1521), a spendthrift member of the Medici family who once spent 1/7 of his predecessors’ reserves on a single ceremony
- Pope Clement VII (1523-1534), also a Medici, whose power-politicking with France, Spain, and Germany got Rome sacked.