Well, Dio respects Johnathan's spirit, courage, and power, but after killing his dog and father and making most of his life a living hell, I don't think murdering someone to live using their body really says "I care about you."
To make use of someone elses body to complete DIO's is probably the utmost care DIO can have, that he chose specifically Jonathan shows it. He thinks of Jonathan as an equal because of how he can still keep up with DIO's evil deeds, even from an Early age.
I think dio respects all them tbh. I don’t think that there’s a “most” as he has different companions and he only cares about the ones which does what he says. If I were a betting man, I would probably say Pucci is the most reliable out of them all. Although Vanilla Ice even sacrificed his life just to give dio his own blood (Dio gave him vampirism in return).
