In Thor Corps #3, when Thor himself is summoned, Jerk with a Heart of Gold Dargo Ktor feels totally humbled at his presence, and bows before Thor. Thor tells him to stand, because all those who have wielded Mjolnir are equals.
In vol. 3 #8, when Thor finds Odin in the afterlife, waging eternal battle against Surtur.
Odin: Odin chooses to stay here and die each day for our people.
Thor: No. This day, father, you shall not die. This day we stand, and fight, together.
Naturally, an epic battle ensued.
Counts as both this and Tear Jerker: The last words of Bill, Born of Bills. He doesn't care that he's going to be honored like a god after death. All he wants is for Balder to make sure to tell Kelda that even after the arguments they'd had recently over the fact that she's an Aesir and he's mortal, he still loves her.
Later, when Kelda dies, she reunites with him in Valhalla. Awwwww...
Thor and child!Loki after Siege. Makes you wish this won't inevitably turn out to be an underhanded plot by Loki or be retconned away to fulfill Status Quo Is God someday.
Turns out the plot wasn't totally underhanded. Loki got sick of how predictable his own damaged psyche made him, and decided to be reborn as a new Loki who would forge a different path.
Old Loki to Kid Loki: Change or die? I would rather die than not change.
Really, Thor deciding to bring Loki back at all despite all he's put him through, and despite what everyone else says. He just loves his brother that much...awwww.
Loki's adoption used to be this. Come on, a king taking in the child of his hated enemy (in most continuities, an enemy that he just killed in an epic battle) and raising the kid as his own? That's beautiful right there. Then it was retconned to have all been a plot by a time traveling Loki, who manipulated events so Odin would take him in-knowing what he would do later. No wonder Odin's patience with Loki has clearly run out in recent issues. Loki really DID cause everything.
Well, the film version still counts.
In The Mighty Thor 12.1 Loki's so happy Thor's back and is cheering. Thor warns him not to strain his throat with all the yelling. Loki's response? "Worth it! Long live the Mighty Thor!" he's just so happy to be with his brother again.
His talk with a priest in Thor: Heaven & Earth #3 1.
The Mighty Thor #338 had the moment when Odin found out that Beta Ray Bill has taken Mjolnir and Thor is trapped on Midgard as Don Blake. After a quick scan, Odin finds his son and instantly teleports him home as his true self. When Thor thanks him, confessing that he thought he was forever stranded without his true form on Earth. At that, Odin gently chides him that a son should have had faith that his father would of course come to help him.
Loki once turned Thor into a frog. The story was played seriously, and even had heartwarming moments as Thor defended the Central Park frogs against an army of rats, befriending them in the process. One of the frogs he helped, Puddlegulp, later gained some of his power and became Throg.
In issue 13 of Jason Aaron's run on Thor: God of Thunder, Jane Foster is revealed to have breast cancer. Thor's immediate response? To hop up and immediately set out for some magical doodad to make her well again. But when she tells him to stop, pointing out that there's no free lunch with that sort of thing and that she's going to fight it the human way, he acquiesces and takes her to the moon.
He also gives a man on Death Row a special fruit from a long dead planet, the last of its kind and unbelievably valuable, as a last meal. It transpires that he's been regularly visiting this man and talking to him for years, and stays with him until he dies.
Thor: I will be with you all the way, my friend. To the gates of the other side.
Hell, the entirety of issue 12 is pure heartwarming.
One of Volstagg's children, Hildy, has a crush on Hogun. He is sweet enough to bring her back a baseball cap from Earth after the Casket of Ancient Winters saga.
In New Avengers #32, as he and Hyperion stand against the Beyonders, he fails to lift the version of Mjolnir he'd been using for the last few issues. The thing is, that Mjolnir was from a mirror universe, where one had to be unworthy to wield it. There's a moment of frustration, followed by a laugh of pure joy as, at the end of the world, he's once again worthy.
Thor: So be it. If this is the end, let me meet it not as the unworthy... but as my father's son.