Scotty pulling an in-universe version of Shown Their Work in Saving Sammy to make a connection with the previously-unreachable Brent Harris and solve his parents' murder.
Miller has Scotty to talk to a guy who has been hanging around a local playground. Scotty talks to the guy and realizes he's a pedophile. After warning him never to come back to the playground, Scott returns to find out that not only has the man returned to the playground, he's now talking to one of the kids he noticed him eyeballing earlier. Without saying a word, Scotty merely gestures to the kid, who instantly knows to get out of there. The next thing we see is Scotty beating the crap out of the guy.
Nadia Kosolov, the victim in "Triple Threat," is standing on a street corner singing Tom Petty's "Free Falling" when her father shows up. When she sees him she transitions flawlessly into "Va Pensiero" from Verdi's Nabucco, a song about freedom and homesickness, then switches back to "Free Falling". Doubles as a Crowning Music of Awesome.
In "Revenge," one of the two cases closed in the episode is that of a pedophile who had raped both his own son and the episode's other victim. As Vera files away his box, he smacks it.
Similarly, in "Justice", as Vera puts away the Asshole Victim box (he was a serial date rapist finally gunned down by the younger brother of one of his victims), he sees the victim's ghost staring at him in disbelief (the cops had convinced the now grown man to claim that he acted in self-defense, thus making it a justifiable homicide, meaning that he wouldn't spend a day in jail). Vera simply sneers at him and walks off.
Rose's Click Hello to her psychotic brother (at the moment trying to strangle her girlfriend) in "Best Friends."
What sells it is her cool-as-a-cucumber declaration that he is no family of hers and her direction to her girlfriend to get into the truck so they can leave. It's an especially awesome moment when you consider that Rose is a) afraid of her controlling brother and b) by far the softer and more feminine of the two women.
The female victim's Famous Last Words in "Who's Your Daddy?" to the creepy construction foreman who had just shot her husband and tried to force her to orally service him: "You. Don't. Exist."
At the end of "The Sleepover," a Sympathetic Murderer, with Scotty's supervision, has a tearful reunion with his sister in the mental hospital to which he has been committed. When their Abusive Parents (who had, among other things, forced the brother to waterboard the sister when she disobeyed them) show up, Scotty slams the door to the brother's room in their faces.
In "Into The Blue," Lilly figures out the case in a hallucination. Mind Screw it may be, but it's also a serious testament to her deductive skill.
Vera and Miller's tag team operation to sneak the deputy commissioner's gun out of his desk in "Shattered".
Pretty much everything about the victim in "Fireflies," especially the fact that she's one of the only two main victims to survive the attempt on her life, and the only one of the two to do so under her own power. Also, she's in grade school..
Maybe it was the wrong thing to do and it was probably traumatizing for him but I can't be the only one who broke into a smile in "Justice" when the young boy shot and killed the bastard who raped his sister (and several others).
Several victims get pretty awesome Final Stands against their killers. Examples include "Family 8108," "Devil Music," and "Strange Fruit."
The scene in The Woods, where Lilly rips apart George's god complex and tells him that for all his bravado and posturing that he's god, he's still just the same frightened little boy who'se mommy abandoned him to be raped by a pedophile and never loved him. While George was angry once before, this is the only time where his mask completely cracks, reducing him to a screaming lunatic begging her to shut up.
Scotty and Vera give the murderer in "Slipping" - a vile piece of work who not only tried to drive his wife to madness to steal her work (recruiting the gullible and lovelorn housekeeper into helping him) and murdered her when she confronted him, but also allowed her daughter to spend 45 years thinking that she had driven her Mom over the edge and that she might go crazy too before wrongfully claiming the Nobel laurate that her work earned - a Massive Reason You Suck Speech outlining just how much of pathetic bag of garbage he really is before arresting the bastard in front of a crowd of people.
The victim of the week often gets one of these in the trailer, or at some point in the episode, just before they turn up dead. Sadly, this is sometimes the very reason they end up dead. (ex: the victim in "Blood On The Tracks" who wanted to confess to a crime committed years ago, but was murdered to ensure his silence, the reporter in "Breaking News" who was about to blow the lid off a scandal, etc.)
The end of "Sandhogs." They track down the killer, a bitter old man, in his favorite bar, where he spends his days drinking, smoking, and pining away for his youth in the '40s. The detectives strike up a friendly conversation with him about said glory days, and then Lilly drops this on him; cue Oh Crap:
"Well, nothing lasts forever... except the statute of limitations on murder."
The victims in "Witness Protection," "Cargo," and "Chinatown" all get posthumous CMOAs for essentially the same reason, in that although they're killed in the process they manage to leave behind clues that ultimately lead to the arrests of seemingly-untouchable crime kingpins.