Louise and Henrietta playing a game of poker in the former's boarding room (just before the Tarbes arc). The stakes are cupcakes from the academy's kitchen. It's such a warm and friendly scene, and the contrast with the usual eventsof their lives underscores how much each treasures these moments.
Tabitha petting Silica's cat ears during the Tarbes arc is so adorable, you'd wish you were there yourself.
Kirito finally meeting with Asuna in Albion and the subsequent Big Damn Kiss. The buildup and followup count as a Moment of Awesome and Funny Moment respectively. It's best summed up in a single word: "SWITCH!"
Once they are safely behind Newcastle's walls, they get a more mellow scene. After the adrenaline passes, they can fully soak up the fact that they are together again, and simply enjoy the others' presence.
King James of Albion showing that despite being a dick and everything that has happened he still loves his son.
The lingering effects of the mana potion on Karin helping her come out of her shell (for a time at least).
She allows herself to feel parental concern and pride for her youngest daughter when discussing her mission to Tarbes, and congratulates her for successfully completing it. The narration notes that she is torn between praising her for stepping up and killing the boss, and scolding her for doing something so dangerous.
Yui greeting her parents as they disembark from the returning ships. Just when it seems that they won't disembark, she sees them and runs to them. There's a flying glomp for her Mama, who embraces her just as tightly, and just as teary-eyed. Then her Papa hugs them both.
Asuna sleeping peacefully in a rocking chair, with Yui curled up beside her.
Kirito and Klein just sitting on the porch, drinks in hand, simply sharing idle chatter, laughing at an off-color joke, or just a comfortable silence... Just being a couple guys, no battles, no disasters, just... peace. note Quoted after Retsof; Post #3717, 6th thread.
Kino mentions during the party that Silica suddenly started rising rapidly in levels. Intuition says it's from Kirito's influence, saying that he did more than save Pina.
Argo hugging Suisen after the latter's blossoming, and the pixie-turned-mousegirl calling her Nee-chan.
Colbert comforting Enya while watching the debates when Alicia finally mentions The Elephant in the Room.
Montmorency and Guiche chatting before the Royal Gala shows depth to their relationship. Guiche is honestly confused about his relationship with "Midori" and Montmorency helps him through it, supporting him with kindness and not once getting jealous.
Mortimer works feverishly to find Sakuya's kidnappers and then insists on leading the unit to the likely location despite fatigue and injuries from his own assassination attempt. He doesn't relax until she's safe with the soldiers. Then he collapses in her arms. Her following Unbroken Vigil and thoughts during are also sweet.
Henrietta's relief upon seeing Sakuya saved from her kidnappers. It goes to show that Henrietta truly considers Sakuya to be a close friend.
It's a mild one to be sure but Kayaba Akihiko doesn't seem to mind Yui referring to him as "grandfather" and the first thing he does in the story is save her life.
Kirito, when asked by Karin about Yui's true nature simply replies, "She is our beloved daughter."
Ch 53 of V.20 focuses on Yui's trip to the Arrun Central Library. Between her impatience in how slow her Aunt and chaperone is, childish delight of books, and just the sight of her walking with Leafa, she is absolutely darling. We also get to see Arrun on a peaceful day, after the shock of the Transition has ended and the shadow of the serial killer is gone.
The meeting between the Triumviri (Lord Mortimer, General Gramont and Count laRemee) is interrupted when 400 pixie knights from 20 gardens volunteer for military service in defence of their home. Remember that a typical pixie is less than 6" tall and uses weapons the size of needles, so they will literally be fighting giants.
Eugene and Morgiana talking outside the Kirigaya's home at the start of the third arc. The two of them exchange their real names and commit to at least trying to make a marriage work.
The Korutaka showing Morgiana that they still support her after she announces her pregnancy and drops her "Big Sis" persona.
Eugene and Morgiana's wedding.
Prince Wales corrects Montmorency when she belittles Leafa's difficulties
“Please, Miss Montmorency, the gulf between two people is never so great for that to be true. Struggles great and small can mean the same thing through different eyes.” The Prince touched Suguha's shoulder gently and squeezed.
After a Djinn calls Asuna Titania, she has a short Heroic BSoD, and seeks Argo's knowledge on the lore regarding the Fae queen. They find that Titania had been originally written as a strong-willed Yamato Nadeshiko, but got retconned by Sugou into an extreme doormat that would give herself to Oberon for the slightest favour. However, it turns out the Djinni still remember the original lore.
(Asuna asks the Djinn to refer to her by name)
There was a moment of silence as the Djinn seemed to parse the question. “Titania. Asuna. Okay! Asuna! Like! Like! Asuna!”
Yui and Asuna looked to one another and then both laughed together. That was how Kirito knew it was going to be okay. “But why do you like me, Djinn-kun?”
The Djinn was quiet again for what seemed like a much longer time. And then its answer came all at once. “Asuna. Asuna! Help! Help. Djinn. Djinn! We! Fight ! We! We! Fight! Oberon! We! Fight! Oberon! We! Win! Desert! Safe! Asuna! Asuna? Right?”
Asuna had gone speechless, so had Kirito. But she'd always been stronger than him as she looked back up with a genuine and tearful look in her eyes. “Un. Djinn-kun. That's exactly right. We won!”
Solomon 'recreating' the djinn that saved Baladene, and her subsequent reaction.
Yui giving Bardiche a peck on the cheek for his bravery in the battle with Octavia.
Yuuki planning what she wants to do now that she has a life to look forward to. Most of those are simple things too, like making snow angels and going to a dance. Then Silica helps her come to the bittersweet realization she can have a home, a family, and a future...
She'd almost forgotten . . . those were things she could have now too, in this sadly happy horribly wonderful world.
Seven year old orphan Pippin clutching a raggedy gray kitten doll to her chest is pure D'awwww.
Tiffania proves her maternal mettle by not backing down until Shiori accepts a Hug o' Healing.
but still, Sakuya giving a cracking Mortimer a Cool Down Kiss is this and a little Tear Jerker.