I cant pick a fav but here's my 5 favs
Johan Liebert, A Nihilistic Serial Killer who is the perfect combination of The Joker, Hannibal Lector, Professor Moriarity, and Michael Myers. He displays a charismatic character, yet deep down he hides a sinister motive.
Griffith, A light villain who is shrewd and ruthless in his ambition, manipulating or disposing of the people who oppose his rise to power without hesitation. He's arrogant and brutally realistic about human nature.
Funny Valentine, the 23rd president of the United States. While his villainousness is not at the same level as the others on this list. I really love his parallels to the other characters in the series, and how it can be argued that johnny joestar is a villain also.
Gustavo Fring, A cold-blooded killer who makes tasty chicken. what more could you ask for?
Meruem, probably one of the best character developments I have seen in a villain. Especially with his parallels to Gon, the protagonists. The way meruem became humane while tearing away at Gon's humanity was really cool to watch.
If i had to pick tho, it would prob be a tie between Griffith and Johan
Who's your all time favorite villain? Could be from books, movies, TV, etc. What is it about them that makes them your favorite?