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!