Anyone on the Law alignment in games with a Law-Neutral-Chaos mechanic is gonna get a LOT of shit for being Knight Templar asshats, especially the angels; contrast those in Chaos, who don't get as much flak for wanting to achieve anarchy-level freedom, and especially Neutral, who like to promote balance rather than one extremity. You'll see quite a few fans enjoying the Neutral and Chaos routes, but rarely ever someone who finds the Law route to be their favorite one.
Here are some from Persona 3, though not all are permanent, some hatred fading over time.
Ken Amada remains one of the least-liked members of the cast for his scratchy and inconsistent voice acting and his distaste for the Ensemble Darkhorse. Perhaps his biggest issue is how he gets Demoted to Extra; after said Ensemble Darkhorse drops out of the spotlight, Amada proceeds to have absolutely no effect on the rest of the plot (including The Answer); his lines could have easily been given to other party members with minimal changes made. Even from a gameplay perspective, Amada gets outclassedin everything he does by everyone else, so he feels pointless to bring over for a fight, unless as a backup for fatigued characters. His P3P incarnation is more well liked, due to giving him a Social Link that gives him a role after being Demoted to Extra (a lot of the Ken related fanart usually involve the female heroine) and the point that he exists just to cause Shinjiro to die becomes moot since he's now savable. However, the fact that the female protagonist can have a relationship with him turns a lot of people off.
Fuuka Yamagishi's English voice can be grating. As your tactical support, you cannot switch her out, meaning you will hear everything she has to say multiple times, long after you've grown tired of it. Her relationship with Natsuki doesn't help matters either, due to Natsuki also having an annoying voice, neither does the fact that the game forces you to date her during her social link (granted, the other female party members' social links inevitably turn romantic, unlike in the two subsequent games, which give you opportunities to confess your love or stay platonic). Most damning of all, however, is how her Oracle skill can randomly reduce your HP and SP to 1 during a fight. It's almost a tradition for P3 fans to shout Stop Helping Me whenever she appears on screen.
The trend continues in Persona 4 with Teddie. Like Fuuka, fans tend to get annoyed by his tendency tostate the obviousin battle with an annoying voice. However, unlike Fuuka, he stops being the Mission Control after Rise is introduce, but there are still some that a good chunk of his dialogue consists of him going on and on about how he wants to get laid. It doesn't help that a goofy cartoon bear doesn't really fit in a murder mystery story.
Rise's in the same boat as far as her Japanese voice acting is concerned, so it's easy to find people who cringe in annoyance at her squealing. On the other hand, she's spared most of the vitriol in the English version, where she's played by fan-favorite Laura Bailey, although some fans find her behaviour around Yu annoying, especially if they ship him with one of the other girls.
Mishima of Persona 5 became one to a lot of people part way through his Confidant line. While he starts off a sympathetic Woobie and the Phantom Thieves biggest fan he starts to show a darker side. Trying to make them target people he doesn't like, and claiming they owe their success to his Phan-site. With even the protagonist's dialogue being clearly annoyed by him. He's saved from the heap by the end though. Coming to his senses without the Thieves stealing his heart, learning to stand up for himself, and showing real character development.
Devil Survivor 2 has Daichi, who, while he does get some badass points and can be a damn good physical attacker with great speed, is still a scrappy for being a male Yuzu expy (he whines even MORE than she did and sometimes has even less excuse). Ironically, the actual female character who takes Yuzu's role in a gameplay sense is rather liked.
Ronaldo manages to garner more hate than Daichi ever will. Mainly because he's a law character for one despite the numerous acts coming off as more chaotic. He comes off as a huge hypocrite in comparison to his "evil" counterpart Yamato who flip flops about his alignment whenever it benefits him such as one moment he says he's willing to save everyone but then the next moment leave JP members to be killed by demons because they side with Yamato. On the sixth day he attempts to shoot fan favorite Makoto which can be prevented which also shows more hypocracy since he doesn't view Makoto as someone worthy of saving in his world. Finally when you decide to join either Yamato or the Anguished One, he flips out on you for not choosing his side. In Yamato's route he tries to kill Yamato after you defeat him fair and square resulting in Yamato retaliating in self defense and sending him off the ledge. This is compared to if you fight Yamato on his path and Yamato's final moments is saving the MC. When he approaches you in the Anguished One's path, he tells you no hard feelings but then flips his shit when you beat him and tries to kill Anguished One thus getting killed for attempting to fight a God. For claiming everyone is equal, he doesn't treat many characters as equal when it's convenient to him.