The scene where Graham cheers up Whisper after losing badly at the Duel of Speed. From a story perspective, he didn't have to do that. He could have just rubbed it in his face that he won. Instead, he gives Whisper what he wants: a fan.
Potentially the Compassion choice with the Dragon during the prologue. After all Graham went through, instead of taking down the enemy who murdered his friend five years ago, he instead shows it mercy and sets it free as a gesture of good will and forgiveness. That is the sign of a true hero!
"In that moment, I forgave the dragon for his atrocious past."
When you find the Merchant of Miracles, if you saved him in the previous chapter, he'll be very happy to see you. Nice to see he's not a complete Ungrateful Bastard.
Right before starting to cross the chasm, Graham does Achaka's salute.
The thing that makes Muriel lose her temper and decide to ditch the smart way and rain hell upon their guards? The Goblins laugh at Chester's poor memory after he accidentally adds the wrong ingredient to the potion. Likewise, Wente getting so riled up over his wife's poor treatment that he's willing to ditch the compassionate way as well.
The Compassion choice ending.
Graham's relationship with Neese if you romance her. Particularly in a Compassion Route, she's every bit the dork that Graham is.
Subsequently, the reaction Neese has when Gwendolyn gives her the perfect gift: a new lute. She's just so touched!
Graham and Vee clearly having a good time trying to out-pun each other.
They still do when they're both old and grey, and Graham is sickly in bed.
Valanice/Vee: Sometimes you've got to keep going until you pancake no more!
Gwendolyn's gift for Vee is a puzzle box which doubles as a music box with an hourglass in it. It seemed like the first time Vee was at a loss of words.
In the climax, Princess Valanice, the princess you pick, comes back to save the other princess, right after she thought she'd made a heroic sacrifice to save her.
The barrier keeping everyone in the tower could only be broken through "true love". Because Valanice and her friend love each other like sisters, they're able to get through the barrier together.
Hagatha was a pretty 2D villainess in King's Quest II. Here it's shown she was locked away by her own parents, and kept waiting for her true love to free her, it never came, and she stopped loving herself. Graham is the first person who shows her empathy, and when she can't exit the tower, he walks out with her.
The lullaby Graham sings to baby Alexander.
The entire chapter shows just how proud Graham is to be a father.
In the present, Alexander has retired from adventuring. The reason? To raise Gwendolyn.
The answer to the final riddle of the sphinx. "What is the one thing worth breaking the bonds of your family?" Graham's answer? Nothing. There is nothing worth that.
If you're doing the Compassion route, Wente and Bramble give you a gift as a thank you for all you've done for Daventry- grandma's Starshroom Pie recipe. And Wente tells Graham, "Nobody outside our family knows this recipe. A fact that will remain true now that you have it." Meaning that Wente and Bramble consider Graham as part of their family.
In the final Duel of Wits, Graham does something that Manny never expected or could have conceived of despite his years of planning: intentionally splashing himself with poison to save his castle, his people, and his family.
Mordack and Graham's interactions. Despite the last time they met where they tried to kill one another (to the point where Mordack still has the facial scars of being clawed at by the tiger form Graham used), they are very cordial and respectful to each other, unlike the contempt that Manny and Graham share.
While Graham is being tortured by Manny for defeating him for the final time, Mordack remembers back to how young King Graham was the actual one to save him from his abuse at the hands of the goblins, and acts for himself for the first time in his life: defying his "brother" and destroying the crystal keeping Manny alive, saving Graham.
Despite losing all of his friends to time, seeing only Whisper, Acorn, and the citizens he aligned with in the Land of the Dead, Graham is actually comforted by an old friend in his final days and his final moments, willingly waiting for him to say his final goodbye to his loving family: Achaka came back for Graham to take him on to his next great adventure...
As part of that final scene, Graham tells Gart that he loves him and is proud of him. Gart's reaction suggests that he's been waiting a long time to hear this.
As Gwendolyn begins her adventure, two of the three items she takes with her are Acorn's wool and Achaka's bow.
At one point during Gwendolyn's adventure, Valanice and Alexander are shown silently watching her through the magic mirror.
Also during her adventure, she meets a kid in armor. This kid happens to be Achaka's granddaughter, Taskia. When Gwendolyn learns of this, she gives Achaka's bow to her, Taskia in turn gives Gwen her own bow, mirroring Graham and Achaka's interactions.
Doubles as a Moment of Awesome. After the credits of the epilogue, Gwendolyn is shown standing triumphantly on a cliff facing the sunset (or sunrise?) holding up Taskia's bow as if she's telling Graham that she finished her first adventure.