Well Kuklinski was quite different, as you said. Most don't even consider him to be a serial killer since he was a contract killer. But yeah, the man was a bad ass for sure!Yeah while I also understand his motivations and like kemper I prefer a similar yet very different killer, Richard Kuklinski. He only murdered men, was 6'5" (196 cm), 300 pound (135 kg) in his prime and would become obsessed with killing anyone that in any way slighted him or his family.
Like the fact that he is very lucid and intelligent when talking about his own crimes not tying to bullshit people like Manson or such. His physical size is also something I can relate to I guess that could be a part of it. I just think I got to like him when reading one of former FBI Agent John Douglas books where he talks about his interviews with Kemper. So I would say he is amongst my favorites but not clearly #1. But then again I don't sit at home all day making lists of serial killers I like ^^