Originally, Desmond was fascinated by Cyr, having never met a vampire hunter before and not even truly believing that such a profession existed. Once he was sure that Cyr wasn't going to kill him, and after spending more time around him, he became fascinated by Cry as a person.
Roy was a great father to Desmond growing up and even as an adult he has a lot of admiration for his dad. Roy, was Desmond's moral anchor growing up and its because of him that he appreciates his human side. He cares a lot that Roy is proud of him, even though he has no reason to worry that he wouldn't be.
Starla wasn't as strong of a parental figure to Desmond as Roy and Amadeus were but he still loves her, though they are somewhat distant. As an adult, Desmond understands why she wasn't a very hands-on parent and he doesn't hold it against her. Though, he would have liked it if they were closer and he's usually the one to make the effort to reach out to her rather than the other way around.
Despite knowing that Amadeus is not a very good person, Desmond still really loves him and considers him a second father. Although he doesn't use most of what Amadeus taught him in his day to day life he is thankful to have grown up learning so many different skills. He also owes all of his vampire knowledge to Amadeus and without him Desmond isn't sure how he would have managed his condition on his own. Amadeus is also still financially supporting him so there's that too.
