Rube always calling George "Peanut". We find out later that he had a daughter whom he also called "Peanut".
Delores becoming jealous of George making any other friends. Probably because George was the only person who could stand to hear about Delores' aging, incontinent cat.
George trying to save the little girl's life in the Pilot episode. The girl herself seems unfazed herself when she skips off to her own version of the Afterlife; a giant theme park.
In "Nighthawks", George remarks that she looks at Daisy sometimes when she thinks she's not and notices how sad she seems.
The whole storyline of "Reaper Madness" and George's interest in the schizophrenic Ronnie. He eventually dies by falling off a balcony onto a just married couple.
Seeing George with her dad in "Sunday Mornings" as he read the sonnets to her and they drank Coke for breakfast. Turns into more of a Tear Jerker when he says he allowed her to eventually drift away from him as he believed she would return to him. She never did.
Also belongs on the Tear Jerker page: In one episode, Mason is assigned to reap a kindly middle-aged gay couple. He strikes up a conversation, and gets to know them, and reaps one of them before he slips, falls, and breaks his neck on the kitchen floor. His partner returns to the room and is horrified. He decides to kill himself, puts on his partner's favorite suit, and when the first dead man's soul tries to get Mason to talk him out of it, he responds with this:
"Every day for thirty years, I've woken up next to that beautiful man. I am not going to go to bed tonight without him. And I am not going to get up tomorrow morning without him."
... which is followed immediately by another one, when, after he prepares to slit his own throat, his partner tells Mason to tell him where he kept pills that could be used for an overdose.
Mason:"Have you thought about ... pills? Because, that looks like it'll be messy, and, well, that's a really nice suit you're wearing..."
In the final episode
George: "I'd be lying if I said I didn't want to be here. Walking through a graveyard, the day after Halloween… on a quiet and beautiful November morning… It's not so bad, being dead like me."
The lights. Anytime anyone goes to their lights, even if it's through tears, it always seems to have that same warm feeling as though you've just arrived home.
Mason saying goodbye to George when he thought when he was getting his lights.
In season 2, Daisy helps a disillusioned priest find his faith again, letting him know that there's more beyond death.