For me I would say “The Expanse” is a huge one. If there was ever a self made family, the crew of the Rocinante is one of the best. The amount of time they spend together and how they congeal into life long partners and friends in the face of some truly awful events is really inspiring to me.
“The Varkosigan Saga” follows generations of family Varkosigan, and their friends-become-family.
Unforgettably eventually arriving at “Miles, where have you left your brother?”
Spoiler for late in the series:
Title
A main character has to deal with an illegally created clone meant to assassinate and replace him…and realizes that his mother will expect him to bring his “new brother” home safely at Christmas, once she learns that the clone exists.