Tommen Baratheon

Throughout his life, it has been fundamentally clear that Tommen's most prominent quality is his innocence. He has been the victim of his older brother Joffrey's intense cruelty, sadism and overindulgence by their mother, and this has set the two brothers apart quite considerably. Where Joffrey was arrogant, monstrous and a dolt, Tommen was humble, gentle, polite, compassionate, kind and sweet to a fault. Tommen was extremely emotional, crying helplessly when his sister Myrcella was sent to Dorne by Tyrion. He didn't stand up for himself when Joffrey callously mocked Tommen for crying, showing that at this point Tommen was underconfident, especially where Joffrey was concerned because Joffrey had tormented his little brother his entire life. Tommen is so kind that he heartily says he doesn't want Joffrey to kill Robb in battle, despite the fact that officially the Starks and Lannisters were in a pitched war with one another.

One of the most unfortunate elements of Tommen's innocence and kindness is that he is considerably easy to manipulate. This set him apart from Joffrey, who was willful and fearsome in his own way and had to be disciplined into following others. Both Tywin and the High Sparrow saw this weakness in Tommen, and exploited it. That being said, Tywin had the decency to say that he thought Tommen would be a much better ruler than his psychopathic older brother was. In this exact same conversation, Tommen is shown to be surprisingly intelligent and didn't require much prompting to figure out what made a good king, without taking it as a criticism as Joffrey would have done. Tommen's intelligence didn't necessarily make him perceptive of people manipulating him, though.