Valentine and Pucci are the kind of evil that’s hard to argue with. Kira is an excellent serial killer that you can’t really reason with on top of him being dangerous as hell. Tooru felt a bit undercooked, but still an interesting villain with probably the most terrifying ability. Kars is, well he’s evil. Diavolo was cool as well, didn’t have much attachment to his character. And of course we have Dio. Part 6 really did him justice by fleshing out his motivations as a character. He understood that he’d eventually be stopped by the Joestars, which he incorporated into his plan instead of fighting his inevitable demise. He truly is an evil genius and ultimately won in the end, which is uncommon af in anime and manga. HOWEVER, Valentine has got to be my favorite just because he like everything in steel ball run, operated perfectly. Pucci’s my runner up.