Americans Hate Tingle: Two Scrappies in North America, Nena Trinity and Marina Ismail, are two of the most beloved Gundam 00 females in Japan, ranking eighth and tenth (respectively) on a April 2008 Newtype magazine poll for the top ten anime females. They were also the only two females from 00 to rank. While both were supplanted by Feldt Grace during the second season's airing, they still remain quite popular.
Broken Base: Other than analyzing the technological aspects of the setting, you'll almost never see any two fans agreeing on anything about this show. Many fans were awestruck by its Super Robot style and emphasis on its message and overtones. Other fans thought it was poorly written with every solution being solved by using a new weapon or power, rather than thinking of a clever solution. And don't get the fans started on the quality (or lack thereof) of the movie...
Cargo Ship: Graham Aker/Gundam. Graham's blatant pick-up lines to the Gundams he encounters while generally thinking of the pilot as an afterthought does not help his case.
There's also Setsuna F. Seiei, who holds his Gundams in a very high regard.
Ribbons Almark is a smug, unbelievably arrogant artificial human who views himself and his fellow "Innovators" as a Superior Species destined to rule over humanity. Setting himself up as a messianic figure (while harbouring even greater delusions of grandeur), Ribbons takes control of the United Earth Federation after betraying Alejandro Corner (who genuinely liked him) and arranging for the death of Aeolia Schenburg, his creator. Almost all of the atrocities that Ali Al-Saachez commits—razing Azadistan, murdering the Trinity siblings (whom Ribbons genegeneered in the first place), attempting to kill all the members of Celestial Being—were done on Ribbons's orders, and once he's ruler of the world, he really comes into his own, ruthlessly manipulating Louise Halevy (a horribly unstable Dark Action Girl) into becoming his pawn, forcing Manchurian Agent Anew Returner into a battle to the death with her Love Interest, using the A-Laws to crush anyone who gets in his way, and utilizing a Kill Sat to murder thousands of people. He do this because it's his way of stroking his own inflated ego. In general he's less a character and more a superiority complex that walks like a man.
Crowning Moment Of Heartwarming: Marie Parfacy's line to Sergei Smirnov in episode 7 of season two: "The Soma Peries inside me has this to say: 'I wanted to be your daughter...'." Also doubles as a Tear Jerker to some fans.
Feldt Grace has a couple of these with Setsuna F. Seiei at the end of both seasons right before the final battle. Said scenes are also where Setsuna and Feldt get their massive level of obligatory Ship Tease.
Any of the opening and ending themes, but especially the final ED "Trust You". Playing it over the loudspeaker system at an anime convention is a good way to garner resounding, sweeping cheers from the entire 'con.
Darkness-Induced Audience Apathy: A complaint lobbed against the series is that many well-liked characters are brutally killed off and that the villains are so unnervingly evil that it becomes hard to care about Celestial Being's cause, especially in the second season.
Ensemble Darkhorse: Fandom loves Patrick Colasaur, and fandom loves Feldt Grace. What more do you need know?
On the Japanese side, Union pilot Joshua Edwards gets a surprising amount of fanart, and is even sometimes paired with Graham Aker in doujinshi. Not bad going for a guy who only appeared in two episodes and got about three minutes of screentime (if that) in total. Oh, and Nena Trinity, in contrast
Ditto for the likes of Sergei and Graham who are badass pilots who can hold their own against the Gundams while piloting "inferior" mobile suits. Their heroic motivations and Anti-Villain portrayals also further endeared them to fans.
Evil Is Sexy: Ali, Hallelujah, Nena, Wang Lui Mei, and Ribbons.
He's Just Hiding: Played around. Episode 10 ends with Sergei Smirnov getting caught in the blast of Memento Mori, making people think he bit the dust. Then in Episode 11, the first scene shows him unscathed. He really WAS hiding... At least until Episode 17. RIP, Papa Bear. And, in a literal sense, Aeolia Schenberg at least until Alejandro finds him.
In the first season, the Irish Republican Army and the Tamil Tigers are mentioned as still fighting, three hundred years later. Barely two years after the episode aired, the IRA ordered an end to its armed campaign and the Tamil Tigers were defeated. But it does say that the fighting has been on and off for years. So maybe justified.
The super deformed omake that parodied the preview of season 2 stated that Lockon would be back as a ghost and that Tieria would be revealed as a robot. Did the writers accidentally spoil the series?
Not only that, the omake also said that there would be aliens, and Setsuna would become Gundam for real. Movie spoilers?
Gundam Meister 874 goes by the nickname Hanayo... wait a minute, didn't Sunrise start an idol franchise with someone named Hanayo? Even funnier now that Love Live Hanayo's seiyuu has done voice work for a Gundam character.
Ho Yay: Despite it being very much one-sided, the fact that Tieria Erde fell in love with the first Lockon Stratos has been near-unanamously accepted by the fanbase. It's easy to see why, too: i.e., in one of the second season OP's Tieria is seen watching over Lockon's Gundam in battle and, at some point, the focus on an increasingly despaired-looking Tieria's face is framed in almost exactly the way a typical Love Interest's face would be.
Over in the Foe Yay corner, there's Ribbons Almark and Tieria Erde. To make matters worse, Ribbons' seiyuu stated that he was told by the directors to deliver the line where he offers Tieria regained access to Veda in a highly erotic manner.
There's also that official poster in which they're gyrating their hips together whilst piercing each others' eyes with deep, hate-filled glares of death...
Speaking of Foe Yay, there's always Mr. Bushido and "This feeling...it must be love!"
Princess Marina Ismail and her lady-in-waiting Shirin Bakhtiar give off significant Les Yay vibes, especially on Shirin's behalf.
These scenes from the Special Edition compilation make the hinted Alejandro/Ribbons canon. It's FUCKING RIBBONS, but yeah.
While they were largely antagonistic to each other in season 1, Setsuna and Tieria picked up quite a bit in season 2 thanks to their quickly warming, friendly relationship, and their teamwork during the dance helped its uptick. By the end of the series it's clear they've become important to each other as seen in Setsuna's grief and desire to avenge Tieria and in the admittedly Base Breaker movie Tieria goes out of his way to protect Setsuna at personal cost.
Hype Backlash: Most of the merchandise released for the series' 10th Anniversary: While the fans praised the PG Gundam Exia, their expectations for the other Mobile Suits (Dynames, Kyrios, Virtue) being made as Master Grade kits (similar to the the ones for Mobile Suit Gundam SEED's 10th Anniversary) was seemingly destroyed after Bandai re-released the HG 00 Gundam in "10th Anniversary" colors (and by extension, the upcoming Megahouse Gundam Guys Generation Lockon Stratos PVC statue), and reuses the mold for one of the kits featured in the Gundam Build Divers series.
Tieria Erde begins as such, before evolving into an Iron Woobie. Sure, he's a smug bastard but the Break the Haughty process he goes through which finishes with the death of the person most important to him (Neil!Lockon) is incredibly harsh and lets everyone see that deep down, he's incredibly insecure.
The Trinity Siblings, as well. The three are terrible assholes to everyone they come across, but they genuinely love each other and it's later revealed that they're Artificial Humans bred and born to be Gundam pilots.Harsh.
If Ribbons didn't crosses it by burning down the neutral Kingdom of Azadistan just so the A-Laws can occupy it, he obviously crossing it by blowing up a space elevator with a Kill Sat to silence thousands of protestors.
Narm: In general, the characters' tendency to switch to Full-Name Basis during dramatic moments is a rich and delicious source of narm. There are plenty of more specific events as well, though:
Marina's song. It's supposed to be very dramatic and heart warming, but most people need to turn down the volume it's so enormously bad.
It is similarly moment-killing how, in the conflict at Point ES-8874 (Ep. 18, where Celestial Being has to fend off the pursuing A-Laws fleet), everyone's pent-up emotions about the people they value just had to cap it with the most aloof characters (and the canon Cargo Ship ones, at that!) in the bunch:
Setsuna's obsession with Gundam counts as both Narm and Narm Charm due to how he often repeats it. For example, in the first season's finale Setsuna makes heartwarming speech only to finish with "We are all Gundam!"
Hallelujah/Allelujah's voice in the English Dub can be a bit unintentionally hilarious especially if the VA himself voiced InuYasha. Brad Swaile as Setsuna F Seiei can sometimes be this too for some fans in certain dramatic scenes.
This can count as Narm Charm. Considering Americans have the reputation of celebrating individuality the most, apparently the show uses this on the Over Flag fighter pilots for their American flavor. (Of note is how they have been albeit-briefly shown not wearing any headgear, giving each more distinct recognition than the generic Red Shirts which are the other soldiers.) The flavor gets a little rich at the moments when one of them gets killed off and a surviving teammate (usually Daryl) has to shout out the just-been-killed-off pilot's name.
Never Live It Down: See if you can talk to anyone about Nena Trinity and not have "the wedding incident" come up. So much that one of the victims (Louise) evolved into a character that isn't unlike Nena in the second season.
On a very similar note, the first thing one will say about Andrei is probably that he committed patricide.
Replacement Scrappy: In story, Lyle Dylandy was this for a while. In fandom he bounces in and out of the trope, since one part of the fandom likes him, another won't stop whining because he's not a carbon copy of his replacee, and yet another hates him because he's too much like said replacee in the wrong places and feels like They Wasted a Perfectly Good Plot.
Nena Trinity, when she provided back up for Setsuna F. Seiei with her shuttle while facing an Innovade, and solidified when she killed WangLiu Mei, an even bigger Scrappy.
She also fares better in certain adaptations that alter her notorious Moral Event Horizon crossing to not be as bad: such as the manga where it actually is an accident (one she shrugs off and feels no remorse for, but still not deliberate) or in Super Robot Wars where all three Trinity siblings kill Louise's parents in attacking a political event under orders, rather than Nena attacking a wedding on a whim.
Lyle/Lockon II (at least for some) did this as he revealed his real abilities, made himself stand out from his brother and show himself as a true beleiver in CB. And all those awesome moments.
For some, Andrei was rescued as well in A Wakening of the Trailblazer, as he genuinely regrets his horrible mistakes and dies heroically.
Romantic Plot Tumor: Saji and Louise in the second season. While it made sense in the first season, it can be argued that they overtook most of the plot in Season 2 with both becoming pilots, and taking time away from other characters that may have benefited more from getting their stories explained.
Rooting for the Empire: In the first seasons its a little hard to root for Celestial Being with their blithe superiority and judgemental attitude, especially given the awesome of people like Graham and Sergei almost beating the invincible Gundams. The second season makes you think this intentional as its all about Celestial Being fixing what they screwed up.
The Scrappy: Even with Louise Halevy's heartbreaking tragedy, she lost some sympathisers by giving into He Who Fights Monsters and joining the villainous A-LAWS. In other cases, some fans don't like her either because she killed Nena, tried to kill Saji, or became a love interest to Andrei for a time. Of course, given the events during the two's only encounter in Season 2, a few fans wound up hating both Nena and Louise in the end.
Ship-to-Ship Combat: Setsuna/Marina vs. Setsuna/Feldt. The fact that the series itself didn't even bother to pick a winner doesn't help at all. However, in the manga based off the movie, Setsuna at the end marries Marina. The mangaka explicitly stated that their marriage is symbolic, representing their deep bond and mutual understanding. The movie is different, without the wedding, and can be seen in a more platonic light.
Stoic Woobie: Setsuna. Near unemotional at first sight, with terrible social skills and an horrifying Dark and Troubled Past. Yet he doesn't complain and, despite tragedy hitting him and his friends more than once, keeps going on.
They Wasted a Perfectly Good Character: Even for those that despise her, there had to have been a point for Nena Trinity to survive Season 1. During the few moments she was seen in Season 2, it appeared that she was developing a conscience and becoming less insane, albeit through a process of ego and seeing even worse individuals, and even did some good for a change by helping Celestial Being destroy Memento Mori and killing Wang Liu Mei. Unfortunately, the Nena/Louise dynamic was never fully explored beyond all the ways Louise wanted Nena to suffer, and ultimately, instead of a grand confrontation where either Nena realizes the horror that others have been put through or Louise realizing the folly of wanton revenge before it was too late, we saw Louise figuratively stuff Nena into a fridge with ease, which makes you wonder what was the point of even developing Nena's character in the first place.
Unintentionally Unsympathetic: Despite a series of unfortunate events hitting them, Louise and Nena ended up being this due to their questionable portrayals throughout the series, especially during season 2.
Values Dissonance: An important part of the characterization of Celestial Being as an organization is that using force to bring peace and a unified world is viewed as hypocritical, and depending on the person a significant drawback or a Necessary Evil. In the US, the acceptability of the concepts of peace through force and world unity are almost flipped.
Viewer Gender Confusion: Hands up whoever thought Tieria Erde was a girl before they heard his voice? In fact, many of the Innovades are guilty of sparking debates far and wide as to their true genders.
It doesn't help that Word of God likes to play cute about the issue in interviews, either.
Ribbons Almarks' Opposite-Sex Clone of sorts, Hiling Care, is an even worse offender of this, but in reverse: despite being flat-chested and showing up at a party wearing a tux, her voice and pronoun usage all indicate that she's female... and it's not until episode 13 of season two that she wears something tight enough to contrast against her AA-cups.
The English dub either ran into this problem or decided to have that last little bit of fun at the viewers' expenses, and made roughly half of them explicitly female.
Wangst: Saji Crossroad, especially in the first half of Season 2.
The Woobie: Marina. Her country is nearly destroyed by a civil in war the first season, and in season 2 she's arrested for having met Setsuna, and then later goes and finds that her country was burned to the ground.