After overcoming the madness caused by the memories of Ashen-Shugar, Tomas goes to visit Queen Algaranna in her bedroom. Prior to this he had angrily send her to her room to await his arrival: this order from a seemingly reborn Valheru being impossible to deny for an elf. Tomas had taken Aglaranna as what was more or less a concubine and has not treated her very well. When he enters the room she thinks he is still Ashen-Shugar, unaware of what had transpired a few moments before. Tomas takes her hand and professes himself her most loyal servant, and Aglaranna sees the change. She forgives him and accepts him, laying the foundation for their marriage later in the book.
Arutha's adventure in Silverthorn, from going all the way to Sarth, Yilth, Elvandar and then all the way to Morealin, the territory of the Dark Brotherhood where he and his team were vastly outnumbered. Why did he do it? To save his beloved, that was his only reason, he didn't care for the risks, he just wanted to save her. YMMV, but this troper was touched that Arutha was willing to risk everything just for the woman he loved.
Pug saying Arutha conDoin is one of the greatest men he ever knew.
Gamina essentially giving up her chance of survival in Rage of a Demon King because she couldn't live without Duke James (Jimmy the Hand) and dying with him.
When Erik, Roo and the others are reminiscing over their fallen companions in Rise of a Merchant Prince.
The ending for Magician's End. Pug is given the chance to return to life so Midkemia will always have a guardian for when there's a threat that needs magic to beat it, but he asks that his son Magnus be saved instead. The gods all agree unanimously and praise and thank Pug for all of his hard work and promise him that they will make sure Magnus is alright without him.
The Empire Trilogy has some moments, but the biggest CMOH must be the end of the Trilogy. It's Earning Your Happy Earning at its finest, especially after all the things that Mara had to go through. To develop (warngin, spoilers) : her son becomes the new emperor and, with her help, they revolutionize the Empire's traditions, changing a lot of bad traditions. In spite of the face that she had to divorce with her loving husband Hokanu, they remain on good terms and he's one of her biggest supports. Her remainging most loyal servants are rewarded : Arasaki gets to live with the woman he felt in love with, Lujan receives a domain (given by Mara herself) and become the head of his own noble house. The enslaved Cho-Ja are now free, thanks to her actions. And, in the last chapter, Mara is reunited with her lover Kevin.