Harry Potter (novel)/Heartwarming

Two Harry-Dumbledore moments that positively ache occur in Half-Blood Prince and Deathly Hallows:

"I am not worried, Harry. I am with you."
"Of course this is all in your head, Harry, but why on Earth should that mean it isn't real?"

Two words: Alice Longbottom.
- Just to expand this, Alice and her husband were tortured to madness so the Death Eaters would know where Voldemort was hiding. In Order of the Phoenix, the gang visit St. Mungo's Hospital after Ron's dad Arthur is bitten by Nagini, Voldemort's snake. Inside, they come in a room where they meet Neville (who did not come with them) and his grandmother. They meet Neville's parents, (whose minds are damaged beyond repair), and Alice, Neville's mother, gives her son a candy wrapper, meaning that after all these years and despite her madness, she still remembers her son and still loves him.
  - Furthered when Neville's grandmother tells him to throw the candy wrapper away ("She must have given you enough to paper your bedroom with,"), but Harry catches Neville slipping the wrapper in his pocket.
Snape's worst memory is his falling out with his best friend. Nothing in all 38 years of his life was as bad as that to him.
- Not just his best friend, the girl he had been in love with from childhood. Think about it - up until that point, Snape stood as much a chance as James did of ending up with Lily, if not a better chance. That would be anyone's worst memory, I think.
One of the best things in the series is the friendship of Harry, Ron, and Hermione. I can't really think of any moments involving Hermione that haven't been mentioned, but there's two with Harry and Ron that make me "aww" every time. The first is in The Goblet of Fire, right after Harry wins the first task. Ron and Harry have been fighting, but Ron comes back after this, and immediately starts complaining that Harry should have gotten more points for fighting the dragon. Harry thinks to himself that Ron's friendship is worth all the points in the world. The second is in The Deathly Hallows when Ron returns after running off, telling the story of how the Deluminator led him back. He says, "I guess Dumbledore always knew I'd leave." Harry says, "No, he knew you'd always want to come back."