it seems that you guys are actually in agreement but arguing over something inconsequential. A good villian (antagonist) is one that pushes the protags to their limit. It doesn't have to be physically (most superhero movies and anime) it can also be psychologically (joker). Everyone likes certain villains for the same reason, not because you sympathize with them, or they have cool powers, or they have a cool laugh, but because they actually challenge the protagonist in more ways than one.