Clannad (visual novel)/Heartwarming

"Fuuko appears!" D'AWWW.
- And, by extension, When Tomoya and Nagisa forget Fuuko for half a day, then remember when prompted by Koumura-sensei. Nagisa shouts out "Fuuko-chan!" and they both turn to see her standing there all along.
Clannad is absolutely packed with these, but episode 18 of After Story takes the cake and eats it too- the scene where Tomoya's estranged daughter Ushio tells him that she has to find the robot he bought for her rather than getting a new one when she lost it because it's her first present from her Papa, and Tomoya tearfully embraces her while promising to be a better father to her reduced me to tears. Followed by Tomoya himself crying openly on the train while telling Ushio about how he met Nagisa. Watch it here.
- Made insanely Tear Jerker level by the Crowning Music of Awesome with Negai wo Kanau Bashou (The Place Where Wishes Come True)'s second version, with the whole orchestra coming in just as Ushio starts crying in Tomoya's arms. And it just continues on as Tomoya recalls Nagisa and finally allows himself to cry over all the good memories.

Tomoya: Nagisa, I finally found it. The thing only I can protect. It was... right here.

Episode 19 of After Story had a couple major ones. In the beginning of the episode, Tomoya spends the day with Akio and Sanae, after finally snapping out of his five-year Heroic BSOD. Akio, during a game of baseball, says it best

Akio: Welcome back to the world of the living, kid.

- And then there's the moment when Tomoya finally reconciles with his father.
The entire middle section of episode 22 of After Story, a montage of the reset button ending that covers where all the characters are now,consists of the biggest ongoing Crowning Moment of Heartwarming in the history of human fiction. It's a Crowning Half-Episode Of Heartwarming. Mere words cannot describe it, but it reduced me to tears AGAIN- tears of pure joy. Especially as up to that point it looked like the series might be going out on the bleakest of Tear Jerker Downer Endings.
After Story Ending: Dango, Dango, Dango, Daikazoku... The whole ending montage when we find out that Nagisa and Ushio are alive makes up for the endless tearjerkers that preceeded it. In a world where the Downer Ending is chic and artsy, it's nice to see a show that isn't afraid to give the characters the Happily Ever After they deserve.
Whenever Ushio has any screentime is made of Crowning Moment of Heartwarming.
Tomoya's marriage proposal to Nagisa:

Tomoya: Nagisa.
Nagisa: Yes?
Tomoya: Let's get married.
Nagisa: ... Yes.
Tomoya: Are you sure?
Nagisa: I've always been thinking that you're the only one.
Tomoya: I'm a guy like this! I'm a really pathetic...
Nagisa: I am, too. But, if we're together, we can become strong.
Tomoya chokes up in tears and hugs her
Tomoya: Will you always be with me?
Nagisa: Yes. I will always be with you. No matter when. No matter how long.

- Submitted for your approval: The Proposal
The baseball scene in Episode 20 of Season 1 (21:25) when Nagisa accidentally confesses her love of Tomoya is just adorable.
The end of Kotomi's arc in season one. After having spent all the years since her parents' death thinking they had loved work more than her and trying to repent for burning what may have been the last remaining copy of their potentially world-changing research, her parents' colleagues deliver something that her parents must have spent their last minutes trying to save just before their plane crashed, abandoning their research so that it could fit in the suitcase: a teddy bear, the birthday present Kotomi had asked her, along with a note written in English leading that whoever finds the bear deliver it to their daughter. Then comes a montage of the note being read in dozens of languages and the suitcase being passed from hand to hand, until it finally reaches the people who will be able to safely deliver it...
I could hardly contain the feelings of pure heartwarming in the last episode of Season 1. When Akio came skidding into the packed school auditorium to deliver one of the greatest of all possible Get a Hold of Yourself, Man! speeches to a crying Nagisa at the top of his lungs, affirmed by Sanae and Tomoya. "We let our dreams become your dreams! Because that's what parents DO! That's what family does!" So amazing it should also be Crowning Moment of Awesome.
- Kyou's and Tomoyo's endings. Earn Your Happy Ending indeed...
- I can't believe no one has mentioned the moment at the end of this episode when Tomoya finally gathers up the courage to tell Nagisa that he loves her. Nagisa's subsequent reaction, combined with the Crowning Music of Awesome in the background led me to fight back tears of joy. This could also count as a Crowning Moment of Awesome.
After Story episode 19. Tomoya finally tells Naoyuki that his efforts to raise a child alone were not in vain and he finally gets some rest.
After Story episode 20 when Fuko visits Tomoya and Ushio and ask's what was her mother like.

Fuko (To Ushio): You've never met your mother, right?
Tomoya: No. She only knows her face from pictures.
Ushio: But I heard stories from Daddy.
Fuko: What kind of person was your Mommy?
Ushio: Ah... A big crybaby. But a person who did her best to give birth to me. And, the person Daddy really loved!

Season 1 episode 9 gives us that scene:

Tomoya: "Doing this really makes us like a family."
Nagisa: "You're right."

Another moment when Tomoya gets Akio and Sanae's blessing to marry Nagisa after Tomoya is able to hit a home run on Akio's pitch
- View Here here.
- It was worth watching him struggle to succeed, it shows he truly loves Nagisa to have as much commitment as he did.
Besides being a Non Sequitur Scene and a Crowning Moment of Funny , each time Fuko shows up after her arc is this in its own way because it show that, even though they don't remember her and she's she's technically in a coma , she will come to her friends' aid whenever she is needed.
Misae's arc in After Story always leaves this troper's heart full without fail even during the sad moments.