Plebian, Repugnant, Impspawn, Loathsome, Irreconcilable, Contemptuous, Malignant, Incessant, Repetitious, Uninspiring, Prejudiced, Cliched, Oppressive, Vaudeville, Pitiable, Arrogant, Ignorant, Pathetic, Miniscular, Cacophonic, Unworthy, Leech, Parasite, really any adjective, adverb or noun with negative connotations can be utilised as an insult if you're creative/evil enough. The wonders of the English language.