In Season Six pilot, Shawn blurts out, on lie detector, that he loves Juliet. This prompts Lassiter to later calmly announce—AGAIN on lie detector, no less—that if Shawn hurts or disrespects Juliet in anyway, Lassiter will shoot him. Repeatedly.
"Which do you think they'd rather have? One million dollars, or 6 more months with you? You know damn well what they will choose, and they won't have to think about it for a second."
This is immediately followed up by another. Dutch The Clutch has been spending the episode trying to kill himself to get a massive insurance payout for his family when Shawn gives him that speech. He's just about to go on another stunt, one that he very much intends to kill himself on...and he doesn't.
The shot of Lassie hugging a crying Juliet after she was almost killed by Mr. Yin.
Also the fact that when you think about it, not only is she crying over the trauma over what happened, but because Shawn didn't come to save her. The look on Lassie's face makes it even more adorable.
Shawn and Juliet conspiring to give Lassiter a confidence boost after he drunkenly spilled his guts to the former. Shawn solves the case, convinces Lassiter that the detective was the one who solved it, and does it all without losing his snarky, here-to-annoy edge.
"A Very Juliet Episode", most stuff with Lassie.
The speech Shawn makes in 3.02.
Shawn: Burton Guster has been my best friend since we were five. And maybe, just maybe, if any of you can look yourselves in the mirror and know that you've been half as good a friend as Gus has been to me, well you too can be considered "Great." Give it up for my best friend, Burton Guster.
Shawn: I can't watch him die. You'll have to kill me first.
Gus: You must be outta your damn mind if you think I'm gonna sit here and die after watching you die...I don't blame you, Shawn. I want you to know that if I had the chance to do it all over again, I wouldn't change a thing. You're my best friend, and we got a chance to live out our childhood dreams. I DON'T BLAME YOU. Okay? And I'm sorry if I couldn't always cut loose the way you wanted me too.
In the episode with Alan Ruck as the bank robber, when Shawn realizes Gus is being held hostage he immediately tries to vault the car and run into the bank. Lassiter and Juliet have to physically restrain him.
Mary:(As he's dying) Do you think they have racquetball in heaven?
Shawn: I know they do.
In that same episode, Shawn and Gus at Mary's funeral, placing racquets on his coffin while wearing gym shorts and sweat bands. Also heartbreaking when you take a moment to realize that apart from the priest and a woman who is presumably Mary's mother, they were the only ones there. The poor guy didn't even have any friends.
At the end of the pilot episode Henry bluntly tells Shawn that he's not okay with Shawn's decision to pose as a psychic detective, "not okay with any of it"... then Shawn's powers of observation notice the newspaper on the passenger seat of Henry's car, open to a big picture of Shawn and a banner headline describing how he solved the big case. Awww, secret man-pride.
At the end of the last episode of the second season, Interim Chief Vick has been confirmed as the permanent Chief and everyone is very happy for her. Even Lassie gives her a non-ironic, heartfelt congratulations. She learns that the mayor was pressured into it as a result of being caught cheating, and the photo credit tells her it was Shawn who did it and they just share a look that just screams "thank you" on the one hand and "you deserve it" on the other.
Henry tells Shawn that he's ruined his fair share of relationships by not communicating and tells him to get off his duff and share it. This is immediately followed by Shawn sharing this with Mc Nab.
Juliet and Shawn have just had this tough case. Juliet is upset over Shawn being a goof and runs outside crying. Shawn intercepts her outside and starts to ramble about how much he loves his motorcycle because of how it's singular, and the freedom, etc.
Juliet: I get it, I get it. You love your motorcycle. Get to the point.
Shawn: Ever since I met you, I've been thinking about buying a car.
So Shawn, and so much "I love you".
"You treat a woman like a person, and then a princess, and then a Greek goddess, and then a person again." Partially because of it being a sweet philosophy that shows Shawn is not just a player, and partially because of it being a Henry/Shawn moment (and one of the few pieces of fatherly advice Shawn took seriously).
The little moments of real concern from Shawn are the best. At the end of "Black and Tan: A Crime of Fashion", when Shawn is talking to Emily Bloom, who is in the hospital after almost dying, and shows legitimate concern that she's all right (and regret that he has to leave when he figures out the mystery) I always want to say "Awwww." Close second: During the exorcism in "The Devil's in the Details...and the Upstairs Bathroom" when Shawn repeats "You're all right, you're all right," to the girl being exorcised—whose mental state nobody else seemed to worry about.
One of my favorite things about Shawn is how those characteristics have always been there, even in the pilot. He's guilt-stricken when he thinks he could have prevented the deaths at the cabin, and he uses his Hyper Awareness to figure out the characteristics of the girl he has a crush on and like her for her personality.
At the end of "There's Something About Mira," when Shawn, Jules, and Lassiter are rushing to save Gus, and Shawn begs them to give him a gun—Gus is in danger!
"You've got it all wrong, man. God's greatest gift isn't adrenaline, it's friendship. I would never do anything to hurt Gus, even if he betrayed me."
The end of "This Episode Sucks": Lassie's been writing a note for the woman he's been involved with for the episode who was stealing blood for her ill brother. He was rather angry, and we're lead to think the letter is an angry breakup note. Then we get to see what he actually wrote: "My dearest Marlowe, I will wait for you for the next six to eight months. See you next Wednesday" All together now: aaaaawww!
Even more heartwarming when you think of Lassiter's attitude towards criminals.
The window love people the window love!
Heck, just the fact that he's smiling. Not in glee over his rivalry with Shawn, not over being crazy prepared, not over anything of that sort at all but simply because he's honestly happy and not angry in the least... that's pretty heartwarming.
At this point, any moment between Carlton and Marlowe can count as this. When we see her again in “Let’s Do-wop It Again” Marlowe and Lassiter are almost the definition of SickeninglySweethearts. You will hate the one “no touching” guard.
A small moment in the episode with the The Bachelor style reality TV parody. Carlton calls out the contestants in his usual way, saying that true love can't be found on television. Shawn pipes up with "The pasty detective is right. True love isn't found on television, it's found in a woman's correctional facility". Lassie takes a moment to smile fondly to himself.
Throughout "Neil Simon's Lover's Retreat", Shawn has been griping about his Nintendo 3DS being stolen. We're led to believe this is him being his normal Man Child self. When Gus retrieves it, he hears an uncharacteristic rattling. Shawn hid an engagement ring in the battery compartment...
In Season 5, Episode 14 "The Polarizing Express" at the end. Henry's fallen asleep and Shawn puts a (pineapple) blanket over him. Furthermore, this is just after Shawn asks Chief Vick to give Henry his job back.
In "He Dead" Shawn asks Henry what he would say if he only had a few seconds to live. Henry starts bumbling so Shawn gets impatient and leaves. After he leaves Henry replies,"I love you."
Shawn and Henry's conversation at the end of "Santabarbaratown", right before Henry gets shot, in which they finally admit to one another that they respect each other as cops.
The forehead kiss. Dear God, the forehead kiss!
A small one, but at the beginning of "From the Earth to the Starbucks", Shawn is on a date with a girl. He uses his observation to deduce that she has just gotten out of a relationship, and she admits that she just found out her boyfriend was cheating on her, describing all the behavior he's been exhibiting to prove it. Shawn puts together the clues and tells her that the boyfriend's not cheating on her — he's getting ready to ask her to marry him, and convinces the girl to call and confirm it. One scene later, the girl runs through the bar screaming that she just got engaged and hugs Shawn, sobbing "Thank you, oh thank you!"
Another small one in "9 Lives": when the killer aims his gun at Gus during the climactic standoff with the police, Shawn sidles in front of Gus to shield him with his body. The completely casual, subtle way he does it makes it even better, as though it were a completely obvious move for Shawn to make.
There's a similar moment in "Heeeeere's Lassie!" when the killer tries to push Shawn and Gus off of a roof. Shawn shoves Gus out of her way first, before acting to save himself.
Shawn's utterly unstrung, frantic, babbling panic when he's trying to pull the limp figure who he mistakes for Gus out of the shallow water of the reservoir in "Tuesday the 17th".
Gus telling Shawn that he loves him, and clinging to him in a tight bear hug for several seconds while visibly holding back tears in "Gus Walks into a Bank".
Before that, when Shawn asks Jules's father for her hand, Frank unexpectedly tells him that, while he likes Shawn, he suspects that he hasn't been completely honest with Jules and he wants her to marry someone who has never lied to her. It shows that, for all Frank's dishonesty, he genuinely cares about his daughter and wants her to be happy.
Also, the bit when Lassie's detoxed from the crazy-gas. O'Hara drapes a blanket around him and asks for anything in the world that could make him feel better, Shawn brings him gazpacho, etc.
The moment in "Santabarbaratown" where Shawn says that his greatest fear used to be something happening to him, followed by something happening to Gus, but Juliet has thrown that all around.
In "Shawn Takes a Shot in the Dark," the moment that Shawn says "Dad!" as he moves forward to rest on top of the car while Henry rushes to him to help him get there. Plus the "If you could just mail me back to my dad, that would be awesome."
When Lassie buys Shawn's motorbike back for him at the end of "Cloudy With A Chance Of Murder."
"Santabarbaratown 2" is chalk full of this. Everything to do with Shawn's geniune concern for his dad, and Lassie of all people helping Shawn with his wacky scheme because it was for Shawn's dad, and he knew he would probably do the same thing.
"I love you...r french toast".
Toward the end of "Juliet Takes a Luvaa", Shawn talks about moving in together, and launches into one of his oddball non-sequitors - this one about pugs - and Juliet is right there with him on it. It's hilarious and heartwarming just how much on the same wavelength they are.
Even though Lassiter's apparent kidnap and possible murder by Bigfoot is Played for Laughs, Jules' utter determination to find him and staunch refusal to believe that he's dead is pretty sweet.
Lassiter, when he thinks he's going to die, gives a speech about how he accepts his mother and her wife, apologizes to Marlowe for not making it out and . . .
Lassiter: O'Hara, you are the best partner I have ever—!
"Deez Nups": Just how deeply and geniuenly happy Lassiter is to marry Marlowe, and vice-versa.
Lassiter: "Marlowe Viccellio, you have given me something to believe in even stronger than the NRA's Code of Ethics."
Also seeing Lassiter sorta admit that Shawn and Gus are his friends.
Also, Lassiter is just so damn pleased to see his friend Stumpy and get a bachelor party.
Then, when Lassie learns that Rizzo (a mob boss Lassie's wanted a long time) has Marlowe and is offering her in exchange for his accountant...
Lassiter: No! I have waited too long for this! We're doing the exchange and I'll just have to get Rizzo another time.
A blink-and-you'll-miss-it moment, Lassiter's mom and her partner both walk him down the aisle during the ceremony and they each give him a kiss on the cheek before taking their seats. Given that Lassie previously mentioned his struggles with accepting his mom's sexuality, it's an extra sweet moment.
The fact that Shawn and Gus threw Lassiter a bachelor party, even though he insists on not having one. Gets even more heartwarming when it's revealed that the only reason he didn't want one is because he didn't have any close guy friends besides Shawn and Gus.
Lassiter's interactions with his dog are pretty heartwarming. It's just too bad it's in an alternate timeline.
A small one, but when Shawn is concussed in "Right Turn or Left For Dead," Chief Vick pats him on the head and makes him tea.
After spending a couple episodes slowly reconciling after their breakup, Jules tells Shawn that the only way they could get back together is if he told the Chief that he's not really psychic. Shawn initially flat out refuses. Cut to the end of the episode where we see that he's about to do precisely that only for Jules to rush in at the last minute and cover for him. If we ever doubted just how far he was willing to go for her, this seals it.
Heartwarming in a different way is that Shawn didn't refuse because of ego or fear of being arrested, but because he wants to keep helping people.
Shawn: That's not gonna happen because if I do that, then all of this goes away. All of it, and with it goes the good. All the lives that I've saved, the lives that I've improved. This is what I have, Jules. This is how I do good.
In it's own way, the fact that Shawn takes it upon himself to draw Jules aside and tell her the truth in "Office Space" counts. Granted, she wasn't happy about it, but it shows that he is making progress in being honest with her.
The Chief ends up suspended so that the others won't be. She's willing to stand by their methods because they bring results no matter how unorthodox or problematic they may be. Shawn gives her a big hug for it. And to top it off, the Chief leaves the office optimistically looking forward to picking up her daughter from school for the first time in months.
Lassiter's reaction to finding out he's going to be a papa!!!
In "Psych: the Musical" when Yang dies, we get to see her in an After Life Antechamber with Mary Lightly!!. Not only do we get to see the Mary again, but he's definitely in heaven, and he's wearing racquet ball gear!
"1967: A Psych Odyssey":
Lassiter and Juliet's last conversation, which also doubles as a Tear Jerker
Juliet: "You're still the chief of police."
Lassiter: "What's it worth? You've never left me out there, not for one day."
Juliet: "You know you have to do this."
Lassiter: "No, I don't. You're still my subordinate, so you listen to me. We have spent eight long years putting our lives in each other's hands. I have watched you fight. I have watched you almost die."
Juliet: "But you didn't let me."
Lassiter: "That's a two-way street. I never would have gotten here without you. You've been so much more than a partner. You're my confidante. You've showed me immeasurable patience and loyalty. You are very important to me, Juliet, and I don't always do a really great job of letting you know that. So I'm telling you now. And you deserve to be this department's head detective just as much as I deserve to be its chief. And I'm not going to do that without you. So I've made my decision."
Juliet: "Me too."
Juliet: "You inspire me, partner. Always have. You have believed in me since day one. You have given me courage and strength and taught me accountability and how to ration my ammo in the event of a nuclear holocaust."
Lassiter: "You're welcome for that".
Juliet: "have a family to think about now. It's time to turn the page, Carlton. And you know what, just knowing you would make that sacrifice for me gives me all the clarity I need."
Lassiter: "What the hell are you talking about?"
Juliet: "Everything happens for a reason. I'm going with Karen. And you are gonna be chief. And it is all gonna be okay."
Every hugging Karen when she says goodbye and Karen asking Juliet to be her new head detective.
"Shawn and Gus Truck Thing Up": The new baby has her first smile after Shawn gives her one of his toys from his childhood. Gus ruins the moment by grabbing the toy back ("Mine!").
The very last few scenes of the series. Gus realizes he doesn't like his new job, and comes all the way to San Francisco to continue being Shawn's partner. Then Shawn proposes to Juliet. Just in time for another Mood Whiplash to end on a funny note.
From the last episode when Lassie is watching the DVD that Shawn made for him, he finally has physical proof that Shawn admits he's a fake. He pops out the DVD before the part where he says it and destroys it.
Then the cherry on top, his last scene is him calling up his wife, telling her to put the baby on the phone, and then in the sweetest voice ever says "Hey Lily. This is daddy".
Earlier in the episode, the new lead detective is balking at Lassie making her choose a partner, in the end she comes to Lassie saying she's finally picked one. It's Buzz.
Also from the finale, Shawn calls Henry to help him catch the killer. Henry just looks so happy.
"He finally called me."
Lassiter and Shawn hug twice in the finale.
"I'm an adventurer now, with a friendship for the ages."
In the third season finale, Shawn tells Gus that he has to act the fool to avoid all the pressure and terror of the case and the general misery of detective work crush him. Gus doesn't hesitate to help him throughout the episode when in normal circumstances he wouldn't dare neglect his own dignity - and Shawn wholeheartedly thanks him for it.