These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Acceptable Targets: Shawn (and possibly the writers) has a vendetta against aloha shirts, and anyone who wears them whether they're a Hawaiian-Shirted Tourist or not. Possibly a Freudian Excuse because Shawn's father often wears them. The writers have a field day with it in "And Down the Stretch Comes Murder" :
Shawn: Wow, Dad, tell me you're wearing that shirt because someone has to spot you from space.
Shawn: A little girl outside just started crying when she saw this shirt.
Shawn: I'm worried someone's going to stare directly at the pattern and have a seizure.
Big Lipped Alligator Moment: In the episode "Let's Get Hairy," Shawn activates a revolving bookcase by grabbing a book. Gus is taken to the other side of the bookcase. It spins back around when Shawn puts the book back. Shawn never notices, Gus never says anything, and the incident is never heard of again.
Complete Monster: Mr. Yin (also known as Karl Rotmensen) is an even more depraved murderer than his former apprentice and daughter Yang. He introduces himself by murdering several people and arranging the corpses in a Yin/Yang symbol. A fan of Alfred Hitchcock, Yin murders a woman named Mary in a manner reminiscent of the famous “Shower Scene” from Psycho. Using this theme as a distraction, he kidnaps the hero Shawn's girlfriend and forces Sean to choose between catching Yin or saving her. When he reappears, he continues attempting to murder Shawn and everyone close to him. What makes him even more monstrous is his sheer pettiness. By his own admission he never loved his daughter, yet he was still angry when Shawn indirectly inspired her to finally stand up to him. He's not angry he lost his daughter, he's angry he lost a tool. It is also revealed that he's the one who made Yang the monster she was, making him responsible for all her murders as well.
Critical Research Failure: In "You Can't Handle This Episode", a guard at a military base reacts with awe when he sees that Juliet's brother has DOD-TS security clearance. While the mistake is understandable—the acronym stands for Department of Defense-Top Secret—it's not actually a particularly high or exclusive level of security clearance (just working at a company that contracts with the military is enough to get you DOD-TS clearance).
Pretty much every single thing about that episode gets the military completely wrong. For instance, the weapons being smuggled out of the armory by the bad guys? Aren't even actual US military weapons - they're visibly H&K G 36 Ks.
The ending scenes of the season 4 finale "Mr. Yin Presents" is the most heartrending sequence in the entire series, thanks to Band Of Horses beautiful track I Go To The Barn Because I Like The....
Ensemble Darkhorse: Mary, the Mr. Yang expert from "A Night with Mr. Yang" and "Mr. Yin Presents." His creepy acting and penchant for saying the most disturbing things made many people wish he would become a regular character. Unfortunately...
Ethnic Scrappy: Tony and Joon from "High Top Fade Out," of "Blackapella," who gave out "free biscuits and gravy" after each show. The latter is even played by Kenan Thompson. And the former is none other than Jaleel White, himself.
Evil Is Cool: Mr. Yin and Mr. Yang. Especially notable as perhaps the only villains in the series who are played completely straight.
Fridge Brilliance: Shawn keeps "hypothetically typecasting" Gus as minor black characters in their favorite movies. This starts when he refuses to let Gus be "Goose" in Top Gun. That's because "Goose" is what Shawn's mother calls him.
In "Juliet Wears the Pantsuit" Henry says he's sorry to Juliette about how things went with her and Shawn. He's not just expressing sympathy, he's apologizing for his part in keeping up Shawn's lie. As much as he can with Lassiter present, anyway.
How did Allison Cowley know that picture was of Yang and a young Shawn? She only knows Shawn from the news coverage of the Yin/Yang case, which wouldn't have included pictures from childhood. She couldn't unless Yin told her.
In "Tuesday the 17th," the initial case turns out to be a prank being pulled on Shawn. But those involved continued the prank after Shawn calls in Juliet, who is ready to shoot the killer if he appears...
Ho Yay: Occasionally between Shawn and Gus. Lampshaded and subverted in Season 4 premiere "Extradition: British Columbia," where Gus comments about the unusually romantic nature of the vacation destinations. As it turns out, they were all arranged for Shawn's girlfriend, but she had a teacher's conference. Shawn and Lassie have a lot of these moments as well. See also Ambiguously Bisexual.
Possibly Lampshaded in "The Head, the Tail, the Whole Damn Episode" when Shawn is telling Lassie he'll help him prove the shark attack was murder, saying they will be like one, and then throwing out several portmanteaus, including Shassie, Sharlton, and Spenciter.
In "9 Lives," a suspect misunderstands Gus's assertion that he and Shawn are "partners." When Gus tries to clarify that he means it in a business sense, Shawn interrupts saying they are in a relationship. He later admits that he does such things just because it bothers Gus. This happened a season before, with Shawn insisting he and Gus really were "lovers in the nighttime".
Shawn: You're in a safe place, surrounded by men who love you. Gus?
Gus: Lassiter, I love you.
A deleted scene from "Daredevils!" shows that Juliet's workout partner, a tough female cop, may have more than a friendly interest in the junior detective.
Shawn even jokes around with Juliet about her sexuality in "Feet, Don't Kill Me Now":
Shawn: Your negativity...is clogging up my psychic signals. Do you mind keeping Tanya note the incredibly flirty receptionist, played by Danielle Harris busy while I attempt to unclog them? Juliet: And how am I supposed to do that? Shawn: Gus would turn into Smooth Gus and try to pick her up. Juliet: I am not hitting on a girl! Shawn: Why, does that scare you? Or does that not scare you...? And does that scare you?
In "Shawn 2.0," while Shawn is giving his dad silly reasons not to hire Declan, he includes his "impossibly long eyelashes."
To be fair, he was played by Nestor Carbonell (Richard Alpert from LOST) for whom the comment is hardly uncommon.
Lauren Lassiter (but with her brother's face, to Gus): You are a great guy. Are you dating anyone?note The bloopers for this scene are hilarious, by the way.
Shawn really wants Lassiter to hug him doesn't he?
Shawn and Gus go Undercover as Lovers, pretending to they were looking for a school for their kid so they could spy on a client's wife who was a teacher.
Informed Wrongness: In "One, Maybe Two, Ways Out," Shawn and Gus are chastised for helping Nadia run from the "good guys"... the good guys who opened fire on them on a pier in broad daylight, while Nadia saved their lives.
Also in Season 1's "He Loves Me, He Loves Me Not, He Loves Me, Oops He's Dead", guest-starring Teryl Rothery.
Nightmare Fuel: Yin and Yang. Yang has been obsessed with Shawn since he was twelve. And her obsession is the only thing that saves his mother in her first appearance.
Add to this the fact that Shawn never knew! She's known about him since he was a kid, knows what happened on the pier between him and Abigail in high school,which implies she's followed him in other episodes since this was only mentioned before in episodes Yin/Yang did not appear in, and Shawn, whose powers of observation are so great that people believe he has psychic powers, never suspected a thing.
Despite being a parody, "Heeeeeere's Lassie" was pretty scary, especially the part where Lassie goes crazy and tries to kill Gus!
"Dead Air" had "Bob" a, Crazy Jealous Guy who was targeting radio hosts who his Ex Girlfriend got too close with. The psych team comes to the conclusion that "Bob" is really just a split personality of his girlfriend (who's bipolar). It turns out there really is a Bob and he shows up at Gus's house with a gun!
The culprit in "Juliet Wears The Pantsuit", an abusive husband whose father was a cop, meaning his wife couldn't get a restraining order, forcing her to go on the run, changing her identity until she decided her only option was to steal the identity of a cop, to keep away from him.
One True Threesome: Shawn/Gus/Juliet is pretty much confirmed in the series finale when Shawn's proposal to Juliet includes "Will you marry us?" since Gus will always be an important part of their lives.
Positive Discrimination: This can also lead into Karma Houdini. Juliet is the only one of the main character who actually believed that Shawn was a psychic. When she found out the truth she helped him keep the lie going. Yet when everything hit the fan she was the only one who wasn’t punished and in fact was promoted while Lasiter was demoted.
Properly Parnoid: Shawn showed mild signs of this when Gus would be interested in a new girl, especially when Gus was in his first real relationship. While Gus and Henry attribute to Shawn being a bit jealous (even Shawn confesses to it,) Shawn isn't exactly wrong to worry considering Gus' judgment is impaired when it comes to women. Several episodes this has occurred and it was once exploited.