Yeah, I guess it comes down to their motive. Dahmer's issues were sexual, I think even the cannibalism tied in with some intimacy thing for him. Ramirez was a classic sadist, like you said. Fish was pretty messed up too haha.
I went through a phase when I was younger, reading a lot of biographies of killers & mobsters. I can't get into it so much anymore, it's kind of traumatizing in a way to see
& hear about people like that & the evil stuff they did.