Most Helpful Guy
I guess I would define it the same as I would for a male player, it would be someone who uses people to boost their own ego and to validate themselves. People are just tools to them, to further their own needs and goals. You are in their life for as long as you are useful to them.2
Most Helpful Girl
A woman who is not able to manage her feelings towards a guy that might be a wonderful guy, a woman that does not deserve to be called a woman with the capital W.
And the same goes for men of course. :)5