The general love and care Chuck gives Katey in the sequel certainly qualifies. For Christ sake, the man constantly risks his own life to get his daughter her Zombrex. If that's not good parenting, I don't know what is.
Giving her gifts as well. It's one thing when a parent goes to hell and back to give their child something they need in order to survive. But you really start feeling the love when you do that same thing to give her a gift. Hell, one gift Chuck can give her costs five grand and another is taming a tiger. You tell yourself you do it for the PP, but we all know we really do it just to see that poor little girl smile.
Also related to Katey, you get a real scare at the beginning when you see a zombie chomping on somebody and you think it's Katey. You shove the zombie off and realize that no, it's the security guy that brought her in there in the first place. Katey's hiding in the closet. It doesn't dawn on you until later that it's likely that the guy told her to hide in the closet while he tried to fight off the zombie to protect her. Granted, it didn't work and he died, but the fact he was willing to risk his life for some random kid he's known for like twenty minutes at best is still pretty heartwarming.
Another moment that could qualify is also related to Zombrex, and it doubles as a crowning moment of awesome for a psychopath no less. Carl the postman seems completely and utterly insane when he finds out who Chuck is (like the rest of the psychopaths, of course)... until you defeat him. All Chuck has to say is that the Zombrex was for his daughter and Carl, without a second thought, signs for it himself. Admittedly, that's very kindhearted of Carl. It's one of but many reasons that Carl is this troper's favorite psychopath.
But he was signing for the bomb he used to blow himself up?
I'm sorry, but he's right. At the start of the encounter you have to sign for a delivery. You know, the ZOMBREX. At the end Carl brings out a packaged bomb after signing for it.
Ending S in Off The Record. After finding out that Rebecca wasn't killed when she was shot, Frank rescues her from TK and leaves with her in his arms.
Frank: Hey, what do you say you and me go break this story wide open?
For Chuck and Stacey shippers, there's something oddly heartwarming about TK, when boasting to the imaginary crowd while Chuck is hanging upside-down, referring to Stacey and Katey as "Chuck Greene's family".
And after defeating TK, all three embrace in a group hug.
Rescuing survivors can be very heartwarming, especially if they say or do something that shows how especially grateful they are for the rescue. One mission that stands out is Barn Burner. Rescuing the stereotypically redneck couple is always a priority for this troper.