One of the true highlights of The Giver would have to be the bond between Jonas and his little sister Lily. It's probably the closest any of the characters in the book get to a realfamilial relationship.
Jonas's father is shown to have a special bond with Lily as well. The biggest example of this is when the latter askes for her comfort object at bedtime toward the beginning of the book. Her and Jonas's mother says she should start trying to sleep without it (as it will be taken away when she becomes an Eight). Their father, on the other hand, goes and gets it for her without hesitation. AWWWWW!
Jonas's relationship to Gabriel, with how determined he is to keep Gabe safe, is pretty sweet too (at one point, he even has a bit of a Freudian Slip and refers to Gabe as his little brother- good thing it was the Giver he was talking to!).
Jonas and the Giver's relationship; just keep in mind that the Giver is the first person to ever tell Jonas that he loves him.
The Giver's relationship with his daughter Rosemary. It's very clear that the latter was the apple of the former's eye and that they truly loved one another, unlike the rest of the parents and children in the community (who literally couldn't even COMPREHEND love). Ironically, one of their sweetest moments is also a bit of a Tear Jerker- Rosemary gives her father a hug and kiss on the cheek before going to the Chief Elder to apply for Release.
Jonas receiving memories of various world cultures, reflecting societies and genuinely happy moments before the Community, especially in the film adaptation. At least up until the memory of elephant hunters and especially the one of the Vietnam War.
In the film adaption, one such memory Jonas experiences is the memory of holding a newly born baby he helped deliver, tearfully smiling upon it. For an 18-year-old, Jonas got to experience the beginning of fatherhood second-hand.
The Giver's favorite memory is of a loving family (grandparents, parents, children and pets) happily celebrating Christmas together. It is this memory more than any other that makes Jonas realize that things must change.
At the end, when Jonas steals Gabriel, saving him from being released
"There could be love."
The song "Together" from the little-heard-of mini-opera, where Jonas teaches Rosemary about love so he can confess his to her. All the while, The Giver is standing over them, reminding them of the most important parts of it: listening, sacrifice, being there for one another.
In the film the Giver grows to care for Fiona as well, to a certain extent, and begs the Council not to harm her.
Jonas and Fiona's budding relationship. It's almost certainly the first kiss in God only knows how long.