Abandon Shipping: Fans of the "L & L" pairing (Lee/Lynch) quickly hopped ship when it was revealed in Season 3 that Lynch is actually a 78-year-old man masquerading as a teenager using cosmetics, surgery, and supernatural assistance.
Is Lee a jerk who only cares for his friends or is he Properly Paranoid?
With The Reveal of VP Victoria's truenature, her decision to give Lee an amnesty day from detention comes into question. Did she do it because she wanted to follow the rules? Or did she do it to cause Lee trouble, since Lee was scheduled to fight the 15th Graders at the same time he would have normally been in detention. There's also the question of whether she was truly oblivious to all of Lee's attempts to get in trouble and back in detention.
Aluminium Christmas Trees: Some people assume "Lee Ping" is a Chinese name rather than Korean, but "Ping" is in fact a Korean surname under the McCune-Reischauer romanization ("Bing" is the same name under the revised romanization). "Lee" also does not refer to the Korean surname, but to the given name derived from the English surname.
Audience-Alienating Premise: The show's initial lack of success outside of Canada (as well as Australia and Latin America) can be chalked up to this. The concept of the show led some to believe it would be little more than a high school Cliché Storm, especially with the first season's heavier focus on teen stereotypes (many of which were set up for the purpose of subversion later on). Additionally, the show's extremely tight continuity made getting into the series after its first episode nearly impossible due to extreme Continuity Lockout, which also turned off many TV networks from picking up the series. Ultimately, the show was cancelled prematurely as a result of these factors, but it remains a highly acclaimed Cult Classic nonetheless, thaks to positive word of mouth from those who did give the show a chance from the start.
Awesome Music: The theme song does a splendid job of pumping you up for the show, matching the series' tone and having some wicked guitar riffs. Pretty much everyone in the fandom will tell you its among the many fantastic qualities of the series.
Holger. His quirky character and goofy antics are incredibly hilarious to half of the fandom and just plain annoying to the other half.
Depending on who you ask, Chaz's narcissistic personality is either so over-the-top that he becomes a hilariously entertaining scene-stealer every time he appears or so unlikeable that he's simply just an unbelievably obnoxious character with no redeeming features.
Bizarro Episode: "28 Sneezes Later". Between Lee believing he's hallucinating/dreaming for most of it (which he probably is... tap-dancing tazelwurm, anyone?) and the faux–Zombie Apocalypse B-plot, it's just...weird. However, it ends up doing a lot of foreshadowing for things to come in the series.
Cargo Ship: The Serpent's Snake and Biffy's phone.
Continuity Lockout: With each episode, the plot becomes more and more intricate as either new characters are introduced, old characters change, or some important plot point is revealed. As a result, jumping into the series without starting from the beginning, or missing one episode entirely, could result in a lot of confusion as to what is occurring, even with the recap at the beginning of each episode.
Crack Ship: Chaz/Tina and Lee/Lynch are surprisingly popular ships.
Cult Classic: The show never got a huge amount of attention (especially in the US, thanks to it being royally Screwed by the Network), but the writing's outstanding quality has gained it a small but strong circle of fans, many of whom continue to hold out for a revival and actively spread awareness for the series. Overall, its generally one of Nelvana's lesser-known cartoons, but also one of its most acclaimed.
Die for Our Ship: With the popularity of Lee and Tina's romance in the fandom, many characters have been crucified for getting in the way of it, namely Brandy (in the first two seasons), Brad (although that is the purpose of his character), and Jenny (once she started becoming a more major character).
Tina and Chaz's cameraman Stepak barely even has any speaking lines in the show, but receives huge amounts of fanart as part of a Power Trio with Chaz and Tina.
While he did get a little more attention in later episodes, Cyrus Xavier still isn't one of the more important characters. That doesn't stop him from getting a pretty decent-sized fandom and a lot of fanart, however. Teletoon even released an exclusive online music video of the show's theme song performed entirely by him!
Stinky, one of the 15th Graders, receives an inordinate amount of attention from fans, despite being one of the least important characters in the series, due to him having such a big heart, his Hidden Depths as an aspiring clown college attendee, and how he saves Lee from a tight pinch on a few occasions.
Fanon: It's not uncommon for fans to depict Cam as bisexual in reference to the fact the creators originally wanted him to be gay. However, some fans take it a step further, interpreting his Casanova Wannabe tendencies as a sort of extreme self-denial of his homosexuality and giving him a coming out/acceptance story instead.
There's some overlap with the fandoms for Gravity Falls and Total Drama as well, due to being a mystery show like the former, being a Canadian cartoon about teenagers like the latter, and being a serialized series like both.
Genius Bonus: Lee has a tattoo of a trigram on his left arm. This particular trigram is "fire", or in the original Chinese, Li.
The show was a big hit in Canada and garnered some of Teletoon's best ratings since Total Drama (with almost the entire fanbase being concentrated there), but poor overseas marketing prevented it from getting fans almost anywhere else (most infamously in the US)... with the notable exception of Australia. In that country, the show's ratings were actually on the same level as those in Canada, becoming so much of a hit that every season following the first was aired in Australia on ABC3 before it aired on Teletoon.
Growing the Beard: Season 1 is overall seen as solid, if a little slow, but still important to watch regardless given the continuity and foreshadowing. Season 2, and especially Seasons 3 and 4 (even moreso for the latter), are viewed as even better however, as the mystery and drama surrounding it intensifies, things start getting Darker and Edgier, and the characters show further growth.
Harsher in Hindsight: Following the discovery that Lynch is Radcircles, all the moments where he acted like some kind of slightly awkward Genius Ditz with his comments, are suddenly much less funny. Not to mention the overall admiration he showed for Lee from near the end of Season 1 onwards.
Hilarious in Hindsight: Season 1's Episode 4 had a picture of Lee picking his nose circulating around the school, courtesy of Insufferable Genius Irwin. Come season 2, and Lee befriends (or re-befriends) Jenny, a girl hypnotized into constantly picking her nose. Then, come season 3, she becomes a recurring character and competes with Tina over Lee's affection.
Ho Yay: Quite a bit, between Lee and Biffy, Lee and Holger, Cam and Holger (as of "Misadventures in Babysitting"), Stepak and Chaz, and Tina and Jenny.
Hype Backlash: While Detentionaire has received overwhelming praise from those who have seen it, there are people who come out of the series finding it to be just mediocre; prominent animation reviewer AniMat, for instance, called it "the ultimate mixed bag" and ultimately gave it a 5/10.
Jerkass Woobie: Barrage, who in the end was just another piece of the puzzle surrounding A. Nigma High, a cyborg who's constantly manipulated by everyone around him, and though he's extremely mean to Lee, not only is he actually a good guy, but he tries to save some of the teenagers - yes, including Lee - on multiple occasions.
Jenny's last name has been interpreted by fandom as "Jerkins" due to her initial introduction. Later episodes and Word of God confirms that it's Jergens.
Steve's last name was originally misconstrued as "Carvey" but was later confirmed to be "Carb".
Love to Hate: Barrage. He was The Heavy for most of the early seasons and constantly making Lee's life a living hell, but he's just so damned hilarious and fun to watch, with Seán CullenChewing the Scenery hard to deliver his hammy lines. Later seasons avert the hate part and crank up the sympathy with the revelation he's Good All Along.
LGBT Fanbase: Biffy is really popular with the western bara crowd, and the amount of attractive high school boys in general helped the show become popular with gay men.
Misblamed: For a long time, many fans believed cancelling the series in response to its poor performance in the US was Teletoon's decision, but in an interview with the podcast Movie Madness, series co-creator Charles Johnston confirmed it was actually Nelvana that made the decision. In fact, he even stated that after the announcement, the Detentionaire crew received a call from Teletoon's executives, who were actually upset about this due to how successful the series was for their network!
Once Original, Now Common: Detentionaire debuted at a time when the idea of a TV cartoon for kids having a heavily continuity-driven storyline with a series-long mystery and a racially/physically diverse cast of characters (including a non-white lead voiced by an actor of color) was in its infancy at best (for context, Gravity Falls would debut only one year after Detentionaire did and Netflix, traditionally considered a bastion for serialized cartoons of such high ambition, wouldn't start premiering original cartoons until 2014). Unfortunately, Detentionaire suffered under the weight of its own ambition, leading to poor distribution and its story being Cut Short. But into the Late 2010s and Early 2020s, cartoons with tight continuity and ambitious storytelling have exploded in popularity, and there has been a vast increase in the number of cartoons starring protagonists of color with non-white voice actors, many of which have developed huge fandoms. Consequently, Detentionaire, condemned to the dustbin of obscurity by its unfortunate treatment outside of Canada, is often seen by those who weren't there to experience it as little more than just another quaint little Canadian cartoon among many.
Charles Johnston: At the time we were doing this, the fact we had a cartoon that would end on a cliffhanger and then the next episode would have a "Previously On" was a big, big deal, because no one had ever wanted to do that. They were always like "cartoons have to be self-contained so they can be played out of order", and we really, really pushed for "Let's make a show like some of the shows that adults were loving like Lost. Let's give the younger generation those kinds of shows you can really get invested in". It was all very new, and it was like winning the lottery to even get this show picked up.
One True Pairing: Lee and Tina to many fans, though there are also those who ship them with other characters.
One True Threesome: With Season 3 and 4's Love Triangle between Lee, Jenny, and Tina, some fans began to ship Jenny/Lee/Tina as a threesome.
Periphery Demographic: For the same reason as the above-mentioned LGBT Fanbase, the show became quite popular with adults and older teenagers (particularly women), despite the series aiming more for the 11-15 year-old demographic seen with a few Canadian cartoons like Total Drama.
Rescued from the Scrappy Heap: Many characters who were initially divisive or unpopular with fans were eventually redeemed by the series in one way or another, thanks to the show's talent for strong Character Development and plot progression.
Lee's mother was often disliked by fans for her often excessive harshness towards her son during the first two seasons, but then came "Clogspiracy", where she rescued Lee from the clog-obsessed Blompkins, showing just how much she truly did care for Lee.
Due to his tyrannical attitude towards the students, Principal General Barrage stood out as one of the fanbase's least favorite characters for quite a while, but many began to sympathize with or even admire him as he was revealed to a hopeless pawn of the true antagonists desperately struggling to shake off their control and showed some truly impressive moments of heroism (such as risking his life to rescue the students in "Welcome to Factory Island", helping Lee fight off the Reaper-mats in "The Dance", and rallying Brandy and Camillio to save the students in "Date with Destiny").
Kimmie was dismissed by fans at first for being little more than a generic Alpha Bitch character, but once she started trying to rebuild her relationship with Biffy and becoming a more developed character in the process, she soon gained a lot more popularity with the fanbase, although she still has more detractors compared to the others listed here.
While Jenny was initially lambasted by fans for being yet another character meant to get in the way of Tina and Lee's romance, she soon became a favorite of many as she began befriending Tina and helping Lee in his mission regardless of her crush on him.
Brandy was probably among the show's least popular characters in Season 1 due to her forcing a virtually nonexistent relationship upon Lee for the sole purpose of social climbing and contributing nothing else to the show. However, Season 2 began to improve her reputation with viewers as she tried to form a genuine bond with Lee to get their relationship to actually work and showed off her competency by providing often critical assistance to Lee and his friends with their missions.
The Scrappy: Brad Von Chillstein. While him getting in the way of Lee and Tina's romance is the whole point of his character, his massive ego and Wrong Genre Savvy attitude get on the nerves of many fans.
Given the age gap between the two, some people view the apparent (but most likely one-sided, since it's pretty clear that he was only using her to get to the Mannifestum) romance between Jenny and the Serpent as this. This hasn't stopped everyone, however.
Beth's braces are perpetually crusted with bits of leftover food, which can make it a bit difficult for the squeamish to watch her speak whenever she's on screen.
The Outcasts' behaviors can be this to some people. Even in-universe, everyone finds them to be squicky (although Jenny eventually broke her nose-picking habit).
Barrage trying to remove the microchip the Council implanted in him. In doing so, he takes off the metal plating on his neck, revealing his organs, muscles, nerves, and even parts of his spine inside!
Despite Jenny becoming a part of the main cast in Seasons 3 and 4, the other Outcasts were ultimately neglected by the show and more or less vanished, which is a bit of a shame, given that Jenny's ascendance into the main circle of characters would have been the perfect opportunity to develop them as well and even expand on their roles in the series.
The Down with Lee Club could have made for some solid minor recurring antagonists for Lee, using their grudges against him as a method of making his investigations more challenging while also developing them (particularly its leader, Irwin, whose enmity towards Lee was a major element of his character). Sadly, beyond a few brief mentions of their existence in the second season, the show never really did anything major with them, despite the fact they never disbanded at any point and still vowed to carry out their revenge against Lee.
They Wasted a Perfectly Good Plot: Niles Peg, the perpetually sleeping detention teacher, being revealed to have attempted to open the pyramid years before the events of the series. This point was actually considered for the plot of Season 4 by the creators but scrapped in the final product, leaving his role in the whole mystery (and the bit where the pyramid's opening causes him to float and utter some kind of chant) ultimately unexplained.
on his left arm. This particular trigram is "fire", or in the original Chinese, Li.