The team reuniting after their parents, and Alex's, deaths and being sent to various foster homes, paticuarlly Chase, who spent months tracking down Old Lace for Gert. Followed up right after they break her out, with the entire team choosing to stay together, as a family.
The Young Avengers/Runaways Civil War arc has a couple.
After Xavin rescues the others from being cut up by the Mad Scientist, he/she procedes to nearly kill said scientist. Teddy stands up to her and insists that it would be wrong and Karolina throws her arms around Xavin when he/she backs down. Later, Xavin thanks Teddy for stopping her, explaining that he/she realized if she went ahead and killed the scientist, he/she would have lost Karolina. She also gives this extremely sweet line:
Xavin: She's beautiful, isn't she? Karolina. She's so soft and tender. She's all that's good in my life...
Heck, any Karolina/Xavin moment could probably count.
Later, while the Runaways and Young Avengers are fighting to escape the lab, a brainwashed alien attacks Old Lace, hurting Chase as a result. To save them, Molly fights off the alien and is thrown against the floor, pretty much leaving her unable to fight back. Chase holds her, assures her that she did good, and promises to protect her. He then turns and fights the alien to keep it away from her. Keep in mind that before this, Chase was still recovering from the death of Gert and had very little patience for Molly.
Molly Hayes has these constantly. More specifically, at one point after Gert's death, she asks the team's car (well, giant frog-robot, but you know) if Gert is in Heaven, and when the robot replies that its GPS program can't locate Gert, this upsets her...but then the robot reprograms its GPS so it can say "Location: Heaven, confirmed". It is so very sweet.
And in the "Dead Wrong" arc by Terry Moore there's another one involving Karolina and Xavin. Karolina is being chased by Majesdanian soldiers who hold her responsible for the destruction of their home planet. She finally decides to stop running and give herself up. Cue the team's hardy protests and Karolina's insistence that she has to go and explain to the Majesdanians what really happened between them and her parents. Then, just as the tears are falling, Molly caps it all off by doing this:
Molly: I want to give you a going-away present, but this is all I have on me. I got it from a box of cereal.
Karolina: A compass?
Molly: You might need it to find your way back to us.
For icing on the cake, we find out on the very next page that it was Xavin, not Karolina, who went with the Majesdanians. All because of his/her love for Karolina.
Xavin: I will take your love with me, Karolina. They will see you in me and realize... we are the way to a new world.
It's also quite possibly the first and only time in the entire series that the two of them share a kiss.