There are many traits that make a good hero, in the traditional sense–strength, cunning, valor, wisdom, and even good looks–but it is often the non-traditional heroes that make the biggest impressions.
The classic case of the unlikely hero is Samwise Gamgee from Lord of the Rings. He’s a hobbit, so he’s small, and has no skill at fighting. He is, to use Tolkien’s own word, “rustic,” and generally unprepared to face the world at large. What he does have, however, is love, loyalty, courage, and determination. Though Frodo carries the ring, Sam carries Frodo–literally, at times–and thereby saves the world.
He is unassuming, humble, and fiercely devoted to his friend. He is the character that simply puts his head down and gets to work, doing whatever it takes to help Frodo accomplish his mission. He is not trying to save Middle Earth, and he is not trying to be a hero, but he goes to heroic lengths to help his friend.
Samwise Gamgee leaves a mark on our hearts specifically because he is not the obvious hero, but rather the hero each of us could find in ourselves.