His ending in IV: he leaves home to go and fight, leaving a note to his Mama, promising to come back "when I won't be an embarrassment for you anymore". The ending shows that he'd sent a letter to her saying he was in Hong Kong, prompting Samantha to fly outto him.
"People still stare at me sometimes, but I don't let it get to me. It's okay to make mistakes once in a while. As long as I get to spend time with my Mama, everything will be just fine."
Shaomei: "Although I care about the town, I care a lot more about you two... So please, don't be so reckless, okay?
Chun-Li's Third Strike ending too. Specially when she has a flashback about how she rescued her kidnapped adoptive daughter (the little girl seen in the prologue) and is seen training her and many other kids.
The friendship between Zangief and Rainbow Mika, especially in the story mode for V. Mika is completely star struck to be tag teaming and training with her idol, and Zangief is his usual big friendly self but with an added dose of Big Brother Mentor and Papa Wolf tendencies toward her. They spend almost all of their screen time together hamming it up and having a good time. Special mention goes to the moment where Mika saves Zangief from a bear attack.
Sakura's ending in SSFIV, she has to leave for home with Dan and Blanka, promising Ryu that they will see each other again. Years later, Sakura, now much older, is walking a dog, sees Ryu from a distance, and happily runs after him.
Balrog of all people has some Pet the Dog moments in his endings in SFIV where he rescues a kid. Come SFV and the two have forged a friendly partnership in crime. It's just refreshing to see Balrog treat someone without any contempt for once.
Every moment between Ken and his family in the SFV story mode, especially the scene where he plays with young Mel at the Kanzuki estate and tries to teach him how to throw a Hadouken.
The Ties that Bind gives us Ryu getting out of his post-Satsui no Hado Heroic B.S.O.D. much to Sakura's joy and the scene at the end where Ryu, having won against Seth, collapses to the floor and is happily tended to by Ken, Eliza and Sakura.