The fact that Jacob Marley, though he cannot be saved, goes through the effort to warn Scrooge so his old friend doesn't go through the same thing he is.
Scrooge's Heel–Face Turn is very smile-inducing, and the ending just makes one want to be a better human being.
Scrooge's flashbacks with him and his sister. He clearly loved her, and the feeling was mutual.
The delight of Mr. Fezziwig's Christmas party, showing a time when a young Scrooge had a chance to enjoy himself and be happy, serving under a Benevolent Boss and surrounded by friends.
The Ghost of Christmas Present lives in the moment and enjoys the day with all his heart, and encourages Scrooge to do likewise.
While the bad future is mostly horrifying and sad, Bob Cratchit relates how he met Fred in the street, who comforted him over his loss and was deeply sorry for it.
Scrooge coming to his family's dinner and showing that he can be kind and generous to his fellow man.
"I will not allow this to happen any longer, which gives me no alternative... but to... raise your salary!" Different adaptations play around with just how into the game Scrooge is when he fakes out Cratchit into thinking he's going to fire him, but even when the audience is in the know that he's changed, you can't help but giggle when he completely floors his clerk with the great news!
The last paragraphs are made of heartwarming.
Scrooge was better than his word. He did it all, and infinitely more; and to Tiny Tim, who did NOT die, he was a second father. He became as good a friend, as good a master, and as good a man, as the good old city knew... and it was always said of him, that he knew how to keep Christmas well, if any man alive possessed the knowledge. May that be truly said of us, and all of us! And so, as Tiny Tim observed, God bless Us, Every One!
Patrick Stewart's version when he goes through the Christmas Present segment. He persuades the Ghost to let him stay to see what kind of games his nephew plays with his friends and wife. Both Scrooge and the Ghost enjoy themselves as they watch the games.
The chorus of "The Cratchit Family Christmas Song" in the Mr. Magoo version. "We'll have the Lord's bright blessing."
The Goodman Theater of Chicago does this show every year. The 2002 production featured a Ghost of Christmas Past as played by a deaf man. At the end, all the cast members sang and signed "We Wish You a Merry Christmas."
In Ms. Scrooge, Ebenita helps give food to a group of homeless people at the end, which is especially poignant since her backstory showed her father had tried to open a grocery store before he died.
The novel The Further Adventures of Ebenezer Scrooge is set 20 years after the original, and is about Scrooge bringing Christmas cheer to London in the heat of June to free Jacob Marley of his chains. He accomplishes this, and the paragraph describing Marley's reaction is very heartwarming.
If a spirit can be said to smile, on that night Marley did. His chain, he said, was considerably lighter thanks to Scrooge's machinations, and growing lighter every day. It was nearly four years before Marley paid his final visit, and on that occasion Scrooge's late partner, overcome with emotion, could only mumble a simple thanks for the rest that was, at last, about to come his way.