And Levi

She's my second favorite character.

Armin gets my vote. People often pick those with talent or strength, but a strength of character and brains can be just as special and needed, especially in times of crisis.
Armin proves himself time and time again, strategy after strategy and on top of brain power he's also brave. People mistake bravery for power, but although Armin is weak, he will still stand up for what he believes in and for the people he loves. And that's why he gets my vote. The man has saved many lives by using his brain way too many times to not be a good character.