A rare find considering the types of characters on the show: in The Nightman Cometh after the waitress denied Charlie's marriage proposal, Frank was the only one who tried to comfort him. But of course it was then rendered null by one line.
Frank: It was a great musical Charlie. You did a great job. She ain't worth it. And by the way, I think that rape scene went really well.
There's a legitimate one at the very, very, very end of A Very Sunny Christmas, which has the gang finally all together for Christmas throwing rocks at trains, and a flashback to a young Charlie and Mac doing the same and being surprisingly sweet.
And also Frank's change of heart and the gangs reaction to the gifts he gets them, especially Dennis' excitement. At least, until the experience is ruined when the presents are all stolen by Frank's old business partner.
While the writers try to avoid showing any thing that can be considered heart warming, the episode "Mac and Charlie: White Trash", ends with the gang cooling off with a fire hydrant, there are no jokes, no mockery, no bickering, all that is shown is a group of friends laughing and sharing a genuinely enjoyable time.
In "The Waitress is Getting Married" even though she acted like a horrendous bitch, and humiliated the waitress in that episode, when her fiancÚ comes back to Dee's apartment and confesses he still is in love with her, the small silent smile on her face was just a little touching.
And, of course, Charlie gives the waitress's would-be fiancÚ, who had only been manipulating her as revenge for being turned down in high school, a gift: a box full of hornets.Awww...
Charlie's reaction in "Charlie: King of the Rats" when the gang makes him a new rat stick is amazing, as is the whole plot of the episode, with the gang coming together to give Charlie a great birthday as thanks for him doing all the dirty work at the bar.
Pretty much the whole episode of "Dee Gives Birth." From Dennis' genuine concern for Dee when she is in labor (even wanting to be in the room when she gives birth) to the looks on the Gangs face when Dee was getting rolled down the hallway, baby in hand. Set to Kate Bush no less. Later, they even laughed at one of her jokes. Who would have thought that IASIP could pull off a truly touching moment?
Same with the couple for who she was a surrogate mother for.
Soon after they meet their real father, Bruce Mathis, Dee and Dennis actually look genuinely happy singing on stage with him at his charity performance.
In "The Gang Goes to Jersey Shore" when Charlie meets The Waitress and they spend the evening together. For a show like this, it's almost too heartwarming to believe. So obviously, it's subverted when The Waitress reveals she was on ecstasy that night, and shuns Charlie the next morning. However, it's Double Subverted, when it's revealed Charlie honestly doesn't care that she was high, and enjoyed the night on its own merit. Aww....
This troper thought it was heartwarming in the latest season finale, when one of the gang's old high school bullies tells everyone that Dennis was not really in the cool group back in high school since all he really did was go and hang out with Mac and Charlie all the time. It really shows that Dennis is friends with those two because he really likes them.
Not only that, but he spent so much time with them that it only allowed him to put in a token effort at being one of the popular kids. Dennis prioritized hanging out with his real friends over even attempting to be popular and stroking his ego, which considering the size of Dennis' ego is really saying something.
Mac's father, despite being sent back to jail because of his own son and then later having Charlie & Mac try to sabotage his parole hearing, tells Mac that no matter what his son has done to him, he will always love Mac.
"The Gang Dines Out" features a surprisingly heartfelt moment from Dennis of all people — who's sorely lacked for Pet the Dog moments in the preceding few seasons — when he publicly confesses that knowing Mac always had his back was a key to building self-confidence in his early years. Inevitably, Dennis fouls it up a little with a tale of sexual conquest better left undescribed here, but it's still a genuine expression of friendship, entirely free from his usual manipulative machinations.
The episode also boasts another extremely rare everybody-gets-along ending, like the aforementioned "Mac and Charlie: White Trash" and very few other episodes in the series. The waiter's downfall instantly mends the divide between Dennis & Mac and Charlie & Frank, and when they find out Dee arranged it by tying the waiter's shoelaces together, they respond with praise and welcoming of a kind that Dee virtually never receives from them. Of course, the joke is that by now, everyone else in the restaurant utterly despises the gang, so that the funniest outcome would be for them to be too absorbed in enjoying each others' company to notice or care. Even so, in its own misanthropic way, this is one of the few truly feel-good endings the show's ever run.