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.
Big Lipped Alligator Moment: The end of episode 13 reveals that Keido is suddenly the Prime Minister of Japan. Uhhhh... what? This is never brought up again.
Creator's Pet: The show itself. The director and production staff are responsible for some much more critically claimed anime, such as Attack on Titan and Death Note, but they admit that Guilty Crown was the one they love the most and had the most fun working on.
Many fans seem to like Shu better as a Jerkass than what he was in the first half of the series.
If people dislike Jerkass Shu, they root for Gai. Even though he clearly Came Back Wrong, and even when he was still alive, he was almost as bad as Shu in full dictator-mode. That doesn't stop people from applauding him for taking away Shu's void Genome even though he's clearly on the wrong side.
Colonel Dan Eagleman, who was one of the only nice members of the otherwise Obviously Evil GHQ organization. Many a fan found his cheerfulness, honesty and giving credit where it was due to be very endearing. Just as many were dissapointed that he was killed off not even halfway through the series, only a handful of episodes after being introduced.
While the official pairing is quite obviously Shu and Inori, many fans actually consider Ayase or Hare as better romantic partners. Some also prefer to ship Shu and Mana.
Fans were also somewhat surprised at the hints of a Tsugumi and Daryl pairing, but quickly embraced it.
At the same time though, some fans are disgusted at how forced the Tsugumi/Daryl pairing is.
Nonetheless, almost none of the fans was satisfied with the abrupt end they put to the ship.
Foe Yay: In Episode 4, Segai sees Shu use Inori's Void and practically has an orgasm. One can wonder who he's referring to: Shu or Inori. Episode 6 shows him flashing back to that moment, focusing on Shu's face, and saying that he feels like he's falling in love for the first time. Really, Segai practically orgasms whenever he sees Shu pulling out Voids.
I Am Not Shazam: Fans are already prone to refer to the power of kings as the Guilty Crown despite this term never coming up in the actual show. For the time being, "Guilty Crown" seems to at most be a metaphorical way to refer to Shu's powers.
The entirety of Episode 15. First Yahiro decides to use a Void Ranking system based on the power readings on a random object they happened to find lying around, when it's been proven that all Voids can be useful given the situation. Then after Shu is confronted by Souta and says he doesn't agree with the system, a paper appearing to show the opposite just so happens to get leaked to the F-Ranked students. When they try to break into a local hospital out of desperation, Shu brings Hare along with him to stop them, even though he has no reason to believe any of them are injured yet and she has no means of defending herself whatsoever. Then when they're attacked Souta seems to lose a few brain cells and decides it's a good idea for him and Hare to run out into the open with Endlaves running about, resulting in Hare's death and Shu's Start of Darkness.
Actually, Shu specifically told Hare and the other students to take cover and hide while he drew the Anti-Bodies' fire. It probably would have worked too if Souta didn't pull Hare out into the open and convince her to try and fix a car that was in plain view of the Endlaves.
Les Yay: Some interpretations of the distant finale has it that Ayase and Tsugumi are married, or at least live together. Of course, seeing as the two of them have shown previously no romantic or sexual interest whatsoever in any female and both have plenty of interest in males, this seems very doubtful.
Love It or Hate It: One of the biggest ones on the last years. It's Guilty Crown an excellent anime with gorgeous work, or a plot-hole rich work that's also stereotypical?
Keido may have crossed it at one of two points—either when he tried to prevent the Adam and Eve of the new world from being an incestuous couple by sacrificing hundreds of children in horrific experiments, or when he murdered his old friend Kurosu in cold blood for no other reason than seething jealousy.
Kurosu Ouma crossed it when he agreed to go ahead with the pregnancy that would kill his wife, so that his daughter could trigger the apocalypse by sexing her new brother up. About the best that can be said is that he wasn't too happy about it afterwards.
In Episode 21, when Shu and the Undertakers are moving out to attack GHQ, everybody is going in large armored trucks, a cool bike, and an Endlave. What does Shu drive? A glorified Segway.
One-Scene Wonder: The student with a fridge Void, only seen during the montage in Episode 3.
Rescued from the Scrappy Heap: Shu and Inori have become more popular in recent episodes; Shu because some fans just feel sorry for the kid after all the abuse he's been put through, and both for taking levels in badass in order to protect each other. To support this both Shu and Inori reached number 1 in their respective sections of the "Newtype" popularity poll.
Shu and Inori. Some people theorize that the number of Ensemble Darkhorses on this show is caused by the fact that people dislike them so much that they leach on everybody else.
Souta immediately dropped to this level when one of his boneheaded decisions got Hare killed.
Arisa and pretty much all of the students picked up a Hatedom after the events of Episode 17.
Snark Bait: The anime series ended up, surprisingly enough, developing a proportionally greater "trainwreck" following than Code Geass despite not being quite as popular overall, as a result of the show having dull or unsympathetic characters, similarly bad twists, an obsession with rape or even more bizarre fetishes and perhaps equal or greater Narm fodder. There's not even a Broken Base this time around.
Strawman Has a Point: In Episode 4, we see that the GHQ really did bail Japan out of serious national crisis, and they are still actively trying to get rid of the Apocalypse Virus, though while doing a bit of military research on the side. They even have an entire medical facility to treat patients who still suffer from the virus, and the people they target are ones who have refused to inoculate themselves, meaning they still act as potential carriers. The GHQ also would not have had any reason to commit the atrocities seen in the first few episodes if their highly valuable and extremely dangerous experimental genetic weapon wasn't stolen by an armed terrorist group.
Of course, it all becomes moot when it is revealed that GHQ were the ones to trigger the Lost Christmas event in the first place.
It seems more because the GHQ leadership is corrupt and have their own ulterior motives. However, Dan is proof that at least some GHQ staff actually believe in GHQ's stated ideals.
Not necessarily the leadership, even though Major General Yan is kind of an asshole. The real villains are Souichirou Keido and the Antibodies who are responsible for the events surrounding the series. See Episode 11, where they were the only ones to suffer no effects from the Apocalypse Virus because of vaccines they had injected themselves with beforehand, and all other GHQ personnel ended up KIA by the Virus because the Antibodies had "conveniently" left them out of the loop.
Superlative Dubbing: Putting this on here may be a bit of a stretch, but the trailer's out, and a LOT of commentors on there feel that the very tiny piece of dubbing they heard is superior to the original Japanese, if not better. But again, it's too early to tell as only the trailer is out.
They Copied It, So It Sucks: The basic setup and much of the first episode did bear a striking resemblance to Code Geass, which caused many fans to complain. Episode 2 somewhat quelled these complaints.
Unfortunate Implications: In Episode 14, to see what Tsugumi's void is Shu pulls it out of her while she is held back by everybody else. She is visibly upset by this, but everyone else is smiling and laughing. This scene is played for laughs. Now remember just how sexualized the act of Shu taking voids is? Yeah.