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.
Alternative Character Interpretation: Was Shinra's father a scientist that was curious about Celty and did dissecting to understand her physiology to better comprehend her body or a Complete Monster who likes dissecting unusual things and getting his son to participate it, leading to a strange Yandere obsession with her.
Speaking of cargo ships and Shizuo, Saika really has a thing for Shizuo. Anytime Anri so much as looks at him, the Empathic Weapon gets terribly excited and begins incessantly whispering, "I love you," in her head.
Haruna Neikawa. Plans to not only murder Anri for petty reasons but also kill her friends and force her to watch for giggles? Check. Is taken totally seriously (unlike Izaya's Faux Affably Evil/Creepy Awesome role)? Check. Is not presented in a positive light? Check. Lacks any positive traits? Checkity check check. And if that's not enough she deliberately stabs her own father and forces him to murder Anri originally. She then calls him useless when he fails. She also constantly talks down on Anri for no reason whatsoever calling her a "skank" that throws herself on the men around her when it would apply to her more. Worse is when Anri shows her why she's Saika and her Abusive Parents, Haruna responds by attacking her not caring what she just saw. The scary thing is she's pretty much a Karma Houdini if you don't count her Humble Pie that Anri delivered to her. To add to this even though Anri spares her, she plans on getting back at her in recent chapters and for what reason? For the humiliation she suffered.
Izumi Ran also qualifies. He not only kidnaps Masaomi's girlfriend and gloatingly breaks both of her legs to get revenge on him, but also delivered a truckload of abuse on his own brother, Aoba, for extremely petty and selfish reasons. Worse still, he has been confirmed to be a sex offender and even threatens to rape Earthworm after already putting her through a massive (though admittedly welldeserved) beatdown. And even worse, he, like Haruna is a Karma Houdini who has yet to receive any retribution for his actions.
Earthworm. Wanting to torture and kill two teenage girls just because their older brother was making a research on her organization, certainly makes her one of these.
Crosses the Line Twice: Seems to be a common theme in Narita's method of characterization; name one main character, and he'll have come up with a quirk or scenario that can topple you out your seat in severalways.
Fan Dumb: Definitely not as bad as other examples, but it appears to be happening more and more among shippers now that Shizuo has a possible Love Interest. Any photo of Vorona is bound to get bashed, even if she's not with Shizuo in the first place. Then there's the Shizaya shippers that claim to dislike Vorona simply because she wants to kill Shizuo, which would likely break his heart in the process, in spite of the fact that Izaya wants to kill him as well and has tried multiple times.
Granted, many people haven't read the novels so their interpretation is simply based on hearsay, which is a form of Fan Dumb in and of itself.
If you look on Fanfiction.Net, Deviant Art or any other poll site, you'll probably notice that Shizuo/Izaya is the most popular. Doesn't help with the Ship Tease that Narita gives to bait the fangirls.
Especially in Japan, Izaya/Namie is increasing in popularity, which is also not helped by the fact that the illustrator Yasuda Suzuhito ships them and has drawn some unofficial art of the two for artbooks and such. He's especially fond of dressing Namie in Izaya's coat.
There's also a pocket of fans who like Celty and Shizuo together, mostly because their excellent chemistry could have the potential to be a sweet relationship.
Foe Yay: Shizuo/Izaya (which is regularly spoofed, lampshaded, teased, and generally dicked around with), Shizuo/Vorona, Mikado/Aoba (which overlaps with Ho Yay, and Namie/Mika. Erika claims to see some between Kadota and Chikage. Kadota is not amused.
Harsher in Hindsight: Celty's comment to Shuuji about Shizuo's strength level in relation to others sounds a whole lot less innocent after episode 22.
Celty:"You know how, no matter how skilled a martial artist is, you can just shoot them and it's over?"
Hate Dumb: all over the place. Let's have a look at the shortlist shall we?
Fans of the novels hate fans of the anime who haven't read the novels, and often bash them on their ignorance or preference for the anime, baiting them for knowing nothing about Durarara until the anime came out and praising the superiority of the novels (especially if anyone likes the anime and doesn't like the novels at all).
Even bashing of the illustrations of the light novel versus the animation in the anime, and the comparative interpretations, or complaining about the adaptation altogether.
The shipping fans are all at each others' throats for their different pairings. Fans of the Shizuo/Izaya pairing get bashed by fans of other shipping pairings and general fans who hate it as either a silly fangirl fantasy built on unrealistic Ho Yay or just deride it because it is Ho Yay - there is a lot of bashing of fanfic and doujinshi by people who haven't even read them just because they don't like the pairing - (go to any forum and suggest that Shizuo and Izaya's mutual obsession and fighting is half a second away from Destructo-Nookie and see the flames fly and the thread burn so badly it gets locked).
Fans of Izaya rage against anyone who thinks he's a despicable Complete Monster. Fans of Izaya as an antagonist are locked in conflict with fans of Izaya who lean towards Draco in Leather Pants. Fans of Izaya who don't like Shizuo and fans of Shizuo who deride Izaya have long abusive arguments over their characters that go on for weeks.
Arguments about character motivations and who is "better" than who catch fire like an open gas leak. Complaints about characters and bashing of the characterization or representation of one in comparison to another.
This franchise attracts so much abusive argumentation and Hate Dumb that it's become a part of the fandom's fabric. If you plan on frequenting Durarara forums, either pick one that is isolated to your interests or buy a flame-retardant keyboard.
Idiosyncratic Ship Naming: "Bacon Lettuce" (a backronym for BL) has been slowly catching on after Narita used the term in reference to Shizuo/Izaya.
Almost every time someone is talking about Izaya, sooner or later "stomping on cellphones" will show up somewhere in the discussion.
Drawing versions of the scrolling artwork in the ending with different series' characters is getting rather popular.
Just like the Izaya example, Shizuo is always depicted throwing around vending machines all the time whenever he gets mad even though he actually throws anything heavy instead, or uses the closest streetsign as a club.
YO YO YO... HEY MAN!
Mikado is becoming this. Especially his pen.
The first ED, Trust Me, has become an art and video meme; people replace the distinctive character chain with characters from other shows.
Memetic Sex God: Many a fan have declared their desire to be punched out of their clothes by the GARtender.
Its obvious from this that Japanese fans feel the same way. (There's also an Izaya version)
Mind Game Ship: Izaya has a canon one going on with all of humanity. His favorite targets, however, seem to be Shizuo and Kida, as well as the girls he forms "suicide groups" with For the Evulz.
Though with Shizuo it's mostly in the anime; in the novels, Izaya truly hates him and states that he would rather be as far away from him as possible. He also hates talking about him in general and seems to get pissed whenever anyone mentions him. Shizuo's the last person Izaya would try to play mindgames with face-to-face - he just tries to get him dead from afar.
Mis-blamed: Saki. The main accusation thrown at her by fans is that she's responsible for Kida dropping out of school and leaving Ikebukuro. In reality, it has very little to do with her. Kida left Ikebukuro because he was too ashamed to face Mikado and Anri after the whole Yellow Scarves incident. The extent of Saki's involvement is giving him a place to stay after he ran away from home.
While this is true for the original novel, the anime's epilogue makes it seem that Kida left to elope with Saki, and the scene with Mikado and Anri, smiling and being oddly understanding of his choice to leave. This also wasn't helped by the anime giving Kida an more angst on the subject of Saki, and basically making Kida bring her up when Mikado and Anri saved him, and ultimately having Kida beat up Horada in order to take revenge for what happened with Saki. This is a big change from the original novels, where Kida beat up the Yellow Scarves in self defense, and after Anri and Mikado arrive the three just sat in silence being happy that they were all right. Anri and Mikado also aren't understanding of why Kida left, because he never brought up Saki with them at all, in fact Saki was never the main focus of Kida's characterization in those chapters. So this case Saki is only Misblamed, if you're talking about the novel, if you're talking about the anime however then yes Saki is at fault.
Izaya crosses it in the back story with his treatment of Saki and Kida.
Granted, to some, he crossed it upon his introduction. Especially in the novels/manga.
Any amount of sympathy you may have for Haruna will be lost after Anri shows her her depressing backstory. Haruna's response? Ruthlessly and remorselessly attacking her with the obvious intent to kill her, laughing maniacally in the process.
Izumi Ran either crossed this when he kidnapped Saki and broke her legs or when he abused Aoba. It's hard to tell which, though.
Never Live It Down: Despite not appearing in the anime, Aoba is best known for getting stabbed with a ballpoint pen by Mikado of all people. This is to the point that, since there are very few official illustrations of him and we don't get a good look at his face, he is usually made recognizable in fanart by his wounded and/or bandaged hand.
One True Threesome: Kururi and Mairu don't seem to mind crushing on the same guys, and they both kissed Aoba. And there's also the Twincest. Of course, this is probably because they don't see themselves as seperate people.
Saki. Many people think that she destroyed the íThree Amigos! dynamic with Mikado, Anri and Kida to the point that Kida left Ikebukuro with her and fails to communicate with the other two as time goes on.
Seiji, Namie and Mika also qualify; fans consider them insane, even by Narita's standards, and even after their subplot was rendered completely pointlessthey wouldn't stop showing up. Namie gets more Scrappy points to many Shizaya fans for "being in the way of their relationship."
Squick: Episode 12, where we are treated to a scene of Izaya playing around with Celty's head, tossing it back and forth in his hands like it's a basketball. Though this doesn't quite amount to the fact that Seiji is in love with it. And that Shinra loves Celty better without it.
The Twincest between the Orihara siblings is extreme Fan Disservice for anyone who doesn't have a fetish for it. It doesn't help that Narita is so blatantly intending it to be fanservice.
Every scene with Simon. Since he's the Token Minority, this is (sadly) to be expected. He's a bit of a Funny Foreigner, but beyond that he's mostly just a victim of casual prejudices.
On the other hand, contrast Simon with Kaztano. If that personality was in Simon's body, that would seem pretty racist. Unlike Kaztano who seems unintelligent on top of the language barrier problem, Simon is just Eloquent In My Native Tongue.
Izaya: "...Simon, you seem like a totally different person when you're speaking Russian."
Celty is to a few fans- she just wants to get her head back. This, on top of how she possesses some human traits and lives like a normal human, except everyone else has a head! Yeah.
Woolseyism: The English dub of the anime changes most of Kida's Gratuitous English uses of the word "erotic" (in reference to Anri) to "boobylicious," particularly in Episode 13. It ends up working better, as "erotic" isn't often used in the same sense in English as he was using it in the original. That, and it's much more in keeping with Kida's personality to make up a word on the spot and then keep using it until Mikado tells him to stop. It also just sounds funnier.