Ron Weasley, for me, has always been the bravest of them all.
To forever be in the shadow of your older brothers is one thing, but to stand in the shadow of your best friend is another. But he never deserted Harry. He pushed aside his jealousy and his insecurities and loved his friend with everything he had. Was willing to not only risk his life, but to die for his friend. That, my friends, is bravery.