As a heterosexual male, "best boy" is a topic I am unlikely to bring up of my own accord, but I would have no difficulty or discomfort engaging on the topic with ladies and/or gaybros.

That said, sometimes a male character is so compelling he gets ironically assigned the title "best girl".

I don't usually bring up this topic, but if someone else does it I'll probably play along. Same deal with "best girl", even if I'm heterosexual and male.

I usually like to discuss the characters' role in the story, how they interact with each other, this kind of stuff.