PKNA #9: after Paperinik was apparently coolflamized and then killed by Xadhoom, only to survive and be back to normality, he and Xadhoom share a moment of peace as he tells her about the legend of the springs that were created by the tears of the Moon. Her expression in that panel clearly shows that she, for once, feels calm and happy.
PKNA #37: Xadhoom entrusting PK with the back-up of her soul.
The relationship between the Raider and his son Trip is "d'aaaww"-inducing. It reaches its highest point when seeing is son is not home (Odin Eidolon has brought him in the 20th century), he aborts the mission at Time 0 to look for him, thus involuntarily preventing his own death. In his priorities, the boy comes before everything else.
At the end of PKNA #21 "Tyrannic", Flaggstar wants to give Paperinik a PBI badge to make him a honorary agent, to thank him for the help he gave. He says he can't accept... unless they make another for One. Double heartwarming because for most of the issue Donald was feeling Overshadowed by AI awesomeness
Despite the horrible things he has done, One keeps on wishing to be able to reach his "brother" Two and share the knowledge they can obtain together. In the end, he absorbs what little of the program of a dying Two is left, because he can't bear to see him completely deleted.
One: "He was my only similar! I never wished to destroy him!"