My list would be:
Betsy!
Betsy!
Betsy!
Betsy!
Betsy!
Betsy!
Betsy!
Why? Being a leader isn't always about leadership and charisma which Betsy has none!
However, she is the most determined stepping stone for other characters and let them step on her so that they can shine!! The best quality of a leader is the spirit of self-sacrifice which she has insane amount of it!!!