Crowning Moment of Heartwarming: Jeff’s actions to end the final battle between Troy and Abed. First is this quote after he suggests using the (imaginary) magical friendship hats he got for them to end the fight:
Troy: We’re not stupid, Jeffrey. We know you made those sarcastically.
Jeff: Yes, yes, and I will roll my eyes at both of you when I put them on your heads because that’s the way I am, but that’s not the way you have to be.
Following that, he walks all the way to the Dean’s office to retrieve the (imaginary) magical friendship hats, remembering that Troy crumpled his up and threw it into the corner while Abed merely tossed it to the side. Because of this, he actually un-crumples Troy’s hat and dusts Abed’s off before returning to them.
Finally, his realization that he would do anything for his friends. He’s shown this tendency since taking part in Pierce’s absolutely insane Spanish Class presentation, but his realization of it is a huge moment of personal growth, especially given his recent backslide into self-centeredness.
Jeff: First entry in my stupid journal. Today I had to run and get two imaginary “friendship hats” from an office. I could’ve just walked around the corner and then come back, but for some reason I actually went all the way back to where they were supposed to be. One was crumpled up a bit. That was Troy’s. The other was just a little dusty, that was Abed’s. I fixed ‘em up, even though I was the only one watching because I settled on a truth today that’s always going to be true: I would do anything for my friends. Which I think is how everyone in the world feels, which finally makes me understand war.