1. Cecil Harvey (Final Fantasy IV)
Few heroes have made the sort of journey that Cecil has. Starting the game as the leader of the Baron Imperial Armada, the Redwings, Cecil only gains strength on his journey. Troubled by orders to attack innocent townspeople and steal their crystals, he rejects his role as a crown-sanctioned marauder and embarks on a journey of personal discovery, spending much of the game setting right what he and his superiors put wrong before it began.
From there, he makes an incredible transformation from Dark Knight (badass, but tainted by evil) into a Paladin, pure of heart and imbued with even more deadly skill, thanks to being at one with the power of light. Cecil is one of the most unquestionably good-hearted characters in the history of Final Fantasy, but he's also one of the most mature, taking on his role as a bringer of peace without a complaint. As he struggles to release the world from the tendrils of evil, he suffers plenty of setbacks and betrayals, but soldiers on.