My old warbird Floydcaster from the 70s is named Fronkensteen. While several have acquired female names, most of my stable actually are named for aerial phenomena or things that fly. A couple of others for supernatural beings or movie characters, and a few because of their color.
I'd been playing professionally for many years before I began naming my guitars. I actually used to feel it was kind of self-important for a player to do that, or at best very corny. Then one special PRS swept me off my feet and I really felt she needed a name (that one is definitely a lady). Within a few years, they all had one to suit their character. Now that I have multiples of certain models - often with very disparate personalities - names help me to differentiate them.