- Laughing Larry's expression as the person who tried to kill him (and accidentally killed someone else with the exploding cigar after Larry gave it away) tells him that his best friend when he was a child drowned because he believed that the $7 submarine would work underwater because Larry had said it would.
- Adam talking to the young boy with OCD who killed his dad.
- Angell's death and Flack's reaction to it.
- The entire episode "Indelible." It was a Sept. 11th 10th anniversary tribute, which should clue you in.
- The pilot, 'Blink,' when Mac goes to Ground Zero.
- "Run Silent Run Deep," the scene where Danny breaks down in Mac's arms after his brother is beaten for wearing a wire.
- "Some Buried Bones," the scene where Reed asks Mac where his mother is buried and Mac has to tell him, "She wasn't..."
- "Flash Pop," the lab techs' tribute/vigil for their colleague who was murdered at the beginning of the episode.
- Every bit of Mac's time with Claire in "Near Death." Just try watching that without a box of kleenex.
- The episode about sex trafficking. One of the victimized girls managed to get a postcard back to her father in the Ukraine begging for help, and he came to look for her. Unfortunately, he ran into the exact wrong person to show her picture to and ended up stabbed to death to keep him from interfering. When the poor girl is rescued and brought to identify his body, she completely breaks down and can only cry and repeat, "I love you, I'm safe."
- Two girls are in a car accident and one dies in the hospital, having been smothered in bed. Mac soon finds it was the mother of the other girl, angered over how her daughter was hurt. Mac has to break it to her that because of mistaken identity on the scene, the heavily bandaged girl was the woman's daughter. She even whispered "Mom?" seeing her mother with the murder weapon but the woman believed she was the friend calling for her own mother and then killed her, with her daughter not understanding why this was happening. The woman's anguish when she realized the truth was heart-breaking.
- The last scene of "Command+P". Just...wow.
- "Battle Scars," when the motive and plan for the murder is revealed. It was a tragic accident precipitated by the victim's insecurities and not realizing that even fake bullets can still kill.
- The third episode of the first season, American Dreamers. The kid was obviously very talented; yet no one knows who he is, and worse no family comes to claim the body which means that despite the forensic drawing of the guy he either has no family, or his family doesn't want to claim him.
- The unidentified victim was killed because the killer desperately wanted more money for the items he was trading to get money for drugs, only to come away with little more than pocket change.
- The parents who have spent years looking for their son, and finally think they've got a lead on him, only to first discover that the detectives aren't looking for their son, then to discover that their son is alive and is a murderer.
- What Klaus Braun /Abraham Klein did to a Jewish family in WWII in the flashbacks of the episode "Yahrzeit." He took a woman's broach that he later sold in his elderly man years and had the entire family killed. After the War, he had to live as a Jew for many years after the events. When he was found out, his son watches as his father is taken away and leaves. Counts as a tearjerker as he has no guilt for what crimes he did in the past, but now has guilt for lying to his family for all these years.
- Mac's proposal to Christine at the end of "Today is Life" is the happiest tearjerker in this series, bar none. After all those long years of grieving, after everything he and Christine have been through together, Mac finally seizes the moment and asks her to share the rest of her life with him. And it's breathtaking.Mac: ...I never thought I'd feel like this again. You're everything that's good in my life. We've been through so much together - I need you, Christine, I want you, I...I can't imagine my life without you. I just want to spend the rest of my life with you by my side. [he goes to one knee] Christine, will you marry me?Christine: [glowing] Yes. Of course I will. [she beams as he stands and kisses her]
Tear Jerker / CSI: NY