Melanie's anecdote involved her identical twin sister Sam attempting to convince Melanie that the latter is an adopted child.
When Guppy first appears (shirtless) in the Shay's loft, Spencer mistakes him for a diminutized Gibby and is utterly alarmed. It does get funnier when an ending credit for an earlier episode involved Spencer "turning" Gibby into a 5-year old (Guppy).
Zigzagged with Freddie's mom, Mrs. Marissa Benson; likewise with Gibby's mom with the name Charlotte (but never mentioned).
iWon't Cancel the Show finally stated that their dad's name is Steven Shay.
Sam mentions her father in "iParty with Victorious," and "iLost My Mind" mentioning that he left the family and she does not know his location.
Unrequited Love Switcheroo: iChristmas. Carly gets really upset over two things in this episode that relate to Freddie. The first is that Freddie has moved on, and no longer is in love with her. The second is that Freddie also appears to have given up on their friendship as well. Not quite a full-blown example due to the Wonderful Life premise, but her lines indicate she is very upset that Freddie is not in love with her anymore.
The Un Reveal: In iThink They Kissed, Carly asks Sam and Freddie if they enjoyed the kiss. Before they answer, Spencer interrupts them, and the question is never answered (although in iKiss they both say they thought it was "nice").
Unstoppable Rage: Sam displays this in iMake Sam Girlier after the bully Jocelyn pushes Carly down and when Freddie manacles her to Gibby in iKiss.
Sam [having been babysitting Ginger Fox's baby]]]: Careful, he's a distance pee-er."
The Vamp: Valerie in iWill Date Freddie uses her feminine wiles to lure Freddie to her web show, temporarily stealing him from iCarly, and goes so far as to try it on Sam. Another example is Missy trying to "break up" Carly and Sam.
Vandalism Backfire: Inverted when Sam thought it was okay to bust through her locker door with a hammer because her combination wouldn't work. It turned out to be Gibby's locker - Sam's was the one next to it.
Very Special Episode: iGet Pranky sort of subverts this. While it may be a more general, subtle "just say no" message, the lack of dramatic seriousness suggests that it's a Take That to other older teen shows like Saved by the Bell.
iMeet The First Lady which will be about the importance of military families.
Victoria's Secret Compartment: In iMake Sam Girlier, a bully shoves french fries down Sam's shirt. After Sam beats her up, she pulls a fry out of her blouse, eats it, and remarks that it's a pretty good place to keep french fries.
Pam Puckett keeps her lipstick inside her blouse.
Viewer Gender Confusion: In-show example in iWin A Date. While Spencer was looking at the emails sent to him by ladies from whynotdateme.com, he remarks that the most recent email sender is 'kinda pretty'. Carly then points out to him that she's really a dude. invoked
Villain Ball: Missy in iReunite With Missy. Missy tries to regain her old "best friend" position from Sam, by treating her nicely around people, but indirectly attacking her in ways that force Sam away from Carly. Sam herself is unsure if Missy is trying to hurt her, or if she's jealous of Missy. The evil plot is ruined when Missy gives Sam a Motive Rant for no reason. This pushes Sam to ask Freddie for help. Carly has no clue until she overhearsMissy gloating about the cruise Freddie gave up to get rid of her.
WHAM Episode: iOMG viciously hits a home run with this, further lampshaded by Carly and Freddie's wide-eyed reactions. While iKiss and iSaved Your Life had reasonable plot devices for the ending scenes, the episode's entirety shoots out the ending into another familiar Nickelodeon show.
WHAM Line: Sam confesses that Freddie is the one "she's in love with" using a kiss.
What Does She See in Him?: In iEnrage Gibby, Carly, Sam and especially Freddie are dumbfounded that Gibby can get someone hot like Tasha as his girlfriend. They all agree in the end that "There's something wrong with that chick."
What Happened to the Mouse?: Sam assaulted an ambassador in iWon't Cancel The Show. Sure, she was in juvie, but that's what always happens when kids get arrested. She still would have had to go to court for a trial and possible incarceration.
Both major Ship Tease moments are this. Sam/Freddie because they haven't (and look like they won't) ever tell the audience if they liked their kiss, and if Carly's feelings really were hero worship or if she still carries those feelings for Freddie.
iStill Psycho: Gibby, after getting stuck in Nora's chimney while trying to get to the cops, is seen at the end of the episode still stuck, with no explanation of how he was pulled out.
Wholesome Crossdresser: Spencer wears Size 10 dresses and, apparently, has his own pair of fake boobs (although he does not keep them in his apartment...). Also, Miranda and Noah crossdressed as the "facial hallucinations" of Spencer and Mrs. Gibson respectively.
Who Names Their Kid "Dude"?: The very first question Sam's mom asks about iCarly after watching it for the first time is "Who names their kid 'Gibby'?"
In iNevel, the titular antagonist mocks Spencer's sculpture, prompting Spencer to mutter "Nevel's a stupid name" under his breath.
Will They or Won't They?: Averted for now. Carly and Freddie get together, but then break up in the same episode. Sam and Freddie get together 3 days after Sam reveals her feelings for Freddie, then they break up again after.
In the end Freddie and Carly get a They Do moment in iGoodbye when Carly kisses Freddie and he celebrates it.
In the series finale, iGoodbye, Freddie calls Sam on the phone, and out of the blue she asks if he is calling because he wants to get back together. After repeated "well, uh, do you?"s, they pretend it never happened.
Written-In Absence: Jennette McCurdy was in the hospital when the cast was taping iWon't Cancel The Show. Thus, Sam was absent in the episode, explained as spending the day in juvie after shoving food into a Mexican ambassador's pants. (Remarkably, this is the only episode of the entire run in which any of the four original cast members are absent.)
Yandere: Miss Ackerman to Spencer in "iHave A Lovesick Teacher".
Marta Trundel, Lewbert's ex girlfriend. Because of her, Lewbert got his wart and was compelled to change his name to escape from her. The woman seemed to be a pretty nice and cool girlfriend you could ask for until her True Colors showed as a manic Control Freak. Lastly, Lewbert was more than happy to stay in prison just to get away from her and smacked a cop to extend his imprisonment.
Nora, who locked the main characters in a recording studio in "iPsycho'.
Yank the Dog's Chain: Freddie wins a competition for the giant locker. He proceeds to do a victory dance of sorts. Then insults Sam. Then they reveal Sam won the competition as well.
Spencer rejoices in getting Chuck grounded by his father Mr. Chambers. Spencer jumps around and whoops, realizing later he remained locked inside the basement storage.
Yawn and Reach: Freddie uses one of these to try and bust a move on Carly in iDon't Want to Fight. Freddie fails, not just because he's Just Friends, but because he's interrupted by a toilet flushing (Spencer saying goodbye to a goldfish he killed). He also arguably started off too far away for a really effective move.
You Just Had to Say It: In iStake Out, Spencer meets his old camp bully again and Freddie asks why Stu is nicknamed 'Spanky'. Spanky shows Freddie why, and Spencer sarcastically thanks Freddie for asking while being spanked in the butt with his own umbrella by Spanky.
You Meddling Kids: Sam, Genre Savvy as she is, mocks Ms. Briggs after she had caught them in her house and blackmails them to guest her on the webshow.
Sam: ...or you could just let us get away while screaming (raises fist with an elderly voice) You rotten kids!
Carly occasionally pulls this on Sam when they have a big fight, most especially in their iconic divorcebreak-up scene in iQuit iCarly. The show even handwaves that Carly is very aware how horrible her best friend can be.
You Should Have Almost Died Instead: Mrs. Benson to Carly in "iSaved Your Life." Even though Freddie chose to get hit by a truck instead of Carly, who he saved, his mom interprets the incident as Carly trying to kill Freddie.
Zettai Ryouiki: Carly rocked a Grade B level of this in iHave My Principals.
Sam got a class D one during their Pathetic Play skit in iSpeed Date.
Zany Scheme: Not relied on as much as othershows in its genre. One however, was Sam and Freddie rescheduling Carly's interview with a private school headmistress to her apartment, setting up a mini-golf course inside Spencer's apartment, inviting two dozen kids over, and getting the kids to think she had a prize hidden on her, done to sabotage Carly's chances of being admitted to the school so Carly wouldn't leave them.
The episode iHave My Principals. After Principal Franklin guested in iCarly which resulted him to be fired, two of the meanest teachers take his place. When the new co-principals create a reign of terror at the school, the iCarly gang connives with all the students. They hatch a plan to have an all-out schoolwide rebellion in order to prove to the school superintendent that their previous principal is much better than the new ones.
Subverted in iScream on Halloween where Carly explains a complicated scheme to gain access to the locked door of Apartment 13-B, but Sam just picked the lock.
Defied in iWant My Website Back. Mandy comes up with a plan to get iCarly.com back from Nevel. As soon as she mentions it involving three zebras, Sam shuts her up.