Tommy befriending Carrie, and Sue wanting to make up with her, although by the end Tommy is killed and Sue is mourning Carrie's death and probably traumatized by Carrie's rampage.
Pretty much all his scenes with Carrie. He's just so patient with her such as sitting with her in the car when she was nervous and teaching her how to dance. Moments before his death he can be seen reaching over to Carrie as if he's trying to comfort her.
Carrie: Why'd you want to?
Tommy: Because you liked my poem.
Which is another point in his favor - after reading her poem in class, the Jerk Ass English Teacher has a laugh at her expense and calls it "weird" and "creepy". Tommy immediately calls him on it before Sue asks him to take Carrie to Prom.
And when they arrive at the prom, at least in The Musical version, Carrie appears to be getting cold feet, at which point Tommy offers to take her someplace else and just hang out there. And considering everything that happened, one can't help but wonder what might've happened if she'd taken him up on that...
The teacher trying to show Carrie how beautiful she really is.
Everyone treating Carrie like an equal and clapping when she wins prom queen. Doubles as a Tear Jerker when we know whats going to happen soon, but still heartwarming to see everyone happy for Carrie.
In the De Palma movie, Sue sneaks into prom and watches Carrie and Tommy dancing together from under the stage. She spends all her time there smiling, happy that Carrie's having a nice night. And though it falls firmly into Nice Job Breaking It, Hero territory, Sue's visit to the prom ends with her seeing Chris set up the pigs blood and goes to warn the gym teacher. The teacher, thinking Sue was just there to cause Carrie trouble, has her thrown out.
I Never Dreamed Someone Like You Could Love Someone Like Me I dare you to listen to that song, or watch that scene and try not to smile or at least get watery eyes.
There must be a God. Could it be he's finally heard my prayers ?
In the second movie, there's what Jesse tells Rachel he loves her while she sleeps after having sex. When Rachel realizes this she ends up saving his life from her own rampage, although it doesn't seem to save her.
In the 2013 remake, Carrie leviates Ms. Desjardin off the floor so she won't be electrocuted like the other students, sparing her life.
Also in the 2013 remake, Carrie nearly kills Sue. But after realizing she's pregnant, she rather gently throws Sue out of the house as she brings it down around her.
Just before that, Sue, having personally witnessed the chaos and destruction, charged into Carrie's house to try and talk Carrie down and get her to safety. Especially when you consider that, for all Sue knew, Carrie was out to kill her too. She had no reason to think she would even make it out of that house alive.
A strange one from the 2013 remake, but after using her powers to lock her mother in the closet, Carrie casually glances at the radio on her way out of the house, causing it to turn on. It's playing "Amazing Grace"; even in the midst of her teenage rebellion, Carrie took time make sure that her mother would be comfortable by letting her listen to her hymns.
Of course, the radio also conveniently served to drown out the noise of her mother's yelling and banging against the door so that Tommy wouldn't hear any of it...Could also double as a Crowning Moment Of Awesome in that she's giving her mother a taste of her own medicine.
Another example from the 2013 remake has Carrie looking up a video about telekinesis on YouTube and watching it in small screen until a boy shows her how to watch it in full screen. That's also the second time we see that someone has been nice to her.
"You Shine" from the musical. Tommy and Sue expressing their complete love for one another and making up for the fact that they won't be going to prom together.