Fridge Brilliance: This aired before the wall actually came down. Alvin said "it was all just a dream, but it doesn't have to be." Eleven months later... dream became a reality.
The scenes of people being reunited with their loved ones.
The end of the episode where Dave dreams about what The Chipmunks would be like without him around. It ends with a wonderful song that shows just how grateful they are to have him. Could also qualify as a tear jerker.
The episode "Sisters" has at least a couple of nice little heartwarming moments, both of which involving Brittany realizing how she mistreated Jeanette:
One of which where Brittany realizes she broke her promise to meet with Jeanette and the pig they're caring for for science class in the park; she comes home to find them asleep on the couch, walks over and gives both of them a kiss on the cheek.
Finally when Brittany is heartbroken over not being accepted in the Sister clique, so Jeanette presents her with a large bouquet of roses.
Brittany: But, Jeanette... I was so awful to you.
Jeanette: You're my sister, Brittany, and real sisters stick together.
Brittany: (Tears; hugs Jeanette) You're the best, Jeanette!
The Chipettes reunited with the Australian girl who raised them in the orphanage before the headmistress kidnapped them.
The Chipmunks reuniting with Dave after escaping from Ian Hawke's cage and replacing themselves with the dolls.
For The Squeakquel:
Theodore and Eleanor moment in Toys For Tots scene.
Shortly after saving Theodore from getting devoured by the American eagle at the zoo, Theordore claims that "one for all, and three for one". Alvin apologizes to Simon for everything, but the latter is reluctant to forgive him, so Alvin grabs Simon and tries to kiss him to cheer him up. Simon finally mends fences with his older brother, and hugs him. Theodore joins his brothers in a huddle, with them ruffling his head. Toby looks at them, happy with the brotherly love.
Toby: Guys, that was huge.
Alvin: He's right. So, are we back to one for all and three for one? (Simon turns his back to Alvin and crosses his arms.)
Theodore: Come on, Simon. Hug it out. (Simon is still ignoring Alvin.)
Alvin: You know, I'm sorry, Si. (beat) Si? (grabs Simon) Don't make me have to kiss you! Because I'll do it. I don't care. (tries to kiss him) Here come the lips. Make-out train is leaving the station. Toot-toot.
Simon: (pushes Alvin away, chuckling) Think I'll take that hug. (hugs Alvin, Theodore joins his brothers in a huddle)
Theodore: (sighs) Guys.
(Toby smiles, happy with the heartwarming reunion.)
Simon comforting a sad-looking Theodore with a hug when being booed by the audience as Alvin, along with the Chipettes, still isn't back yet.
Simon holding Theodore and spinning him around while performing "We Are Family" with Alvin and the Chipettes.
The pep talk Simon gives to Dave in the hotel room bathroom while he's getting dressed in formalwear, as Simon tries to explain Alvin's insecurities.
On the island, Alvin feels tearfully remorseful of his mischievous shenanigans shortly after he builds his shelter (a wooden stick hut). Brittany comforting the dejected and heartbroken chipmunk (even though she's not trying that hard) is arguably one of most heartfelt moments of their relationship on the franchise so far, and it proves that Brittany truly cares deeply for Alvin and their friendship beyond just his romantic attraction to her.
Their relationship has become progressively less antagonistic and more genuine towards the end.
Dave's heart-to-heart chat with Alvin, consoling his tearfully remorseful and heartbroken chipmunk son. He's only hard on him because Dave truly loves and cares about Alvin and his safety, and wants what's best for him. Despite being a nuisance, he still loves him no matter what. Their embrace, rescuing each other in the climax and Alvin's apology on the raft is very uplifting.
For The Road Chip:
Alvin and Simon embracing Theodore for sacrificing himself by saving Miles's life after he was knocked down by an oncoming car.
Miles initially starts out quite jerkish and enjoys bullying the chipmunks and coldly snarking at them. Following his Enemy Mine with the boys, he shows more of a heart of gold and gradually becomes more affable, helpful and brotherly to them over the course of the film through his HeelFace Turn and Love Redeems.