How Hanson offers to go to El Salvador with Doug—at that time a civil-war-ridden country—when Doug says he wants to go look for his wife there. Doug himself is hesistant about Hanson coming, as it is dangerous, but Hanson makes it clear he will stand by his friend—and he does; they get into a few life-threatening situations in El Salvador, but stand by each other.
And then how Doug decides to adopt Clavo when they are in El Salvodor and find out Doug's wife has been murdered, but do meet his wife's sister and her son Clavo. Doug is consequently shown in his remaining episodes to have taken Clavo home and to care for him, giving Clavo a new life.
There's something oddly sweet about the fact that, in spite of the time spent ripping the premise a new one, the film is incredibly faithful to its predecessor: it reunites the core cast even if two members get shot to hell, insists that the church is the same and any decor changes are only due to it being leased out, and even making its lead the son of a short-lived and forgotten first season character.
The training montage, with the development of Jenko & Scmidt's friendship.
When Jenko activates the phone tap & overhears Schmidt struggling to ask Molly out, he seems so proud when he actually manages to spit it out. Of course, the moment's ruined when he overhears Schmidt making fun of him.
"Doug, I know sometimes I was a jerk to you when we were undercover. I just...I didn't feel good about myself. All the stuff I wore like, the bracelets, the rings, the tight pants. It was just so that people would think I'm cool. The only approval that I ever needed...was my best friend."
Meta: One of the two things Johnny Depp requested in exchange for reprising the role of Tom Hanson? That they had Peter DeLuise return as Doug Penhall.