Dom's appearance at the end. Doubles as a Tearjerker when you take Han's role in the rest of the series into consideration.
Dom: I won it from our friend Han a few years ago.
Sean: I didn't know he was into American muscle.
Dom: He was when he was rolling with me.
The team congratulating Brian and Mia on their expected child, in particular Dom hugging Brian and Mia.
Dom talking fondly about his father to Brian and after Brian explains that he can't remember anything about his, Dom tells Brian he'll be a good dad.
Dom's speech during the gathering the night before the supposed heist, saying that money comes and goes, but what's really important is the people in the room right now with him as the camera pans to everyone in the room, before they toast for the newfound 'family'.
Vince's last words to Dom about his son Nico. They named him after Dominic.
Dom and Letty's reunion, from Dom jumping to save her from falling (which also doubles as a CMOA) to them talking at the barbecue at the end.
Hobbs coming to respect Dom so much that he held a Spanish Commander at gunpoint to force the release of Shaw to protect Toretto's little sister, held hostage by Shaw's goons.
Brian and Mia comforting Han as the latter weeps Manly Tears for the death of Gisele, right after seeing Dom come out alive at the conclusion of the fight with Shaw. Mia notices that Gisele is missing, asks Han "Where's Gisele?" twice. She immediately understands the answer from Han's radio silence and goes to hug him. Brian quickly follows suit, wrapping Han in a brotherly embrace.
Dom and Hobbs' farewell to each other.
Dom: Not bad for a cop.
Hobbs: I'd never thought I'd trust a criminal. Until next time.
Dom: Until next time.
Han makes the decision that he's going to Tokyo, stating that it's something he's gotta do. He and Gisele constantly talked about going to Tokyo before she died, meaning this is his way of honoring her memory. Following this, Tej and Roman promptly pledge to Han that they have his back if he ever needs them.
The ending for Fast 6 with Brian, Dom and Mia finally getting to return to L.A. together and have a barbeque with the team (including Letty). Bonus points for Brian casually making Roman say grace for taking a first bite and neither Dom nor Mia complaining about how they should do it, with this presumably being their first table meal since returning to the family home.
The Grace part is also a callback to the BBQ in the first movie where Jesse went for the first bite.
In short, rescuing Letty and reuniting her with Dom may have been the focus of the movie from an emotional standpoint, but we see plenty of evidence that all the crew members are family to each other.
Dom & Brian's squabbling over the type of car that Jack's going to like when he grows up.
A meta Heartwarming Moment: after Paul Walker's tragic death, the film's completion was in doubt. However, it has been announced that not only is the film going to be completed and dedicated to his memory, but Walker's character will be written out and given a happy ending.
At one point, Dom quips "I don't have friends... I got family." - a simple line asserting that his crew are his True Companions. In one trailer, this line is played over a series of shots of the primary cast, before hanging on the (at the time) recently deceased Paul Walker as the second part of the line is said.
After the final battle, Dom is left unconscious, with everybody fearing that he might be dead. Letty cradles Dom's body and reveals she's finally regained her memories, and remembers their secret wedding in the Dominican Republic. During the ceremony, Dom doesn't actually have a ring to give to Letty, so he instead gives her his crucifix.
The entire ending is this and tearjerker: As the group sits around on the beach and watches Brian and Mia play with Jack, they realize that they have their own family to build on, and Dom leaves without saying goodbye. At an intersection, Dom thinks about everything he and Brian had been through together, with footage from all the previous movies playing over a goodbye monologue. Brian pulls up next to Dom, asking if he was really going to leave without saying goodbye. The two of them appear to race down the road until they approach a fork, and the two of them split up. Fade to white, with two words on screen: ForPaul.
It might seem like a minor gesture, but the way Brian instinctively closed the car door within moments of the explosion to protect his child made this troper feel warm inside.