If I'm not mistaken, we've so far had more than twice as many male champs (5) as we've had female champs (2), so the answer seems pretty obvious to me. Bring on the girl power. EDIT: If you want to count Red, we've had three times as many male champs.
The champ should be an old man. When you first meet him on your journey he stomps in the ground in battle and afterwards he takes you in as his disciple. You have many nice and memorable moments during the story, so that it has more of an impact, when you encounter him in the champions room.