Charlie's moment with Don while seeing the victims in "Vector". Tell me you don't want to give them both a hug.
In "Noisy Edge", Don tells Charlie that their dad likes to play golf with Charlie (who is an abysmal player) because it's the only thing he can teach his mathematical genius of a son. At the end of the episode, Charlie has renewed enthusiasm for the game and tells his dad "What can I say? You're a good teacher." Awwwwwwww!
Everyone saying goodbye to Larry before he goes into space, and him going off with Buzz Aldren and them toasting his lift off.
The Season Finale for the fifth season of NUMB3RS. Charlie. Proposed. To. Amita. After everything else that had happened in that episode, too... I mean, yeah, it was almost impossible to not see it coming, but... gawd...
Many of the NUMB3RS episodes, at the end, since they usually have a nice touching family moment of the Epps together.
"Dreamland": Alan, Amita, and the heirloom passed to daughters. So sweet.
Even though Dwayne Carter was essentially a villain who betrayed his country, he proved himself a true friend to Colby, saving him at the end of "Trust Metrics". This is despite the rescue meaning Dwayne's certain death and how Colby had turned him into the cops before.
In the same episode before that, Charlie was supposed to list data on reasons to trust or distrust Colby and see which outweighs the other. What does it say? Nothing they don't already know in their hearts.
"The Fifth Man" was pretty much a Crowning Episode of Heartwarming between Don and everyone else.