Throughout the years, I came to my own conclusions regarding The Borg's idea of Perfection.
Throughout all of the dealings The Federation had with The Borg, it is evident that The Borg have weaknesses, they rely on adaptation and assimilation.
In my opinion The Borg assimilate the strengths and knowledge of various species to overcome their weaknesses in order to dominate the galaxy. The Borg Queen has shown both her desire and egotistical ways of dealing with more powerful species or individuals in search for this perfection.