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.
Angst? What Angst?: Eragon in Eldest. It is revealed to him that his father was The Dragon to the Big Bad, and to put it lightly, not a nice person. He gets over this in three paragraphs (although, in fairness, he does revisit it later). He does, however, angst when his uncle dies (for a few chapters, after which he gets over it), when he is told that his father was really his mentor, Brom, and when Murtagh joins the enemy.
There's also Arya in Eragon: in spite of having been, by her own admission, beaten, tortured, and very nearly raped for weeks on end, the biggest reaction we get out of her thereafter is a paragraph of her clenching her jaw a bit as she recounts the events... and after that everything's just peachy, although that may be a racial thing for her.
Well, it has more to do with Arya being a Stoic person in general.
Ass Pull: The series features a big 'un in the shape of magical elf twins, never previously mentioned who cure Eragon's achy back scar, allowing him to fight properly again. They turn up once more in the fourth book make it so Dwarfs and Urgals can become Riders as well, thus solving all racism forever.
Critical Research Failure: Oromis' explanation of the Ancient Language gets basic points about language wrong: "The suffix o forms the past tense of verbs ending with r and i. Sköliro means shielded, but skölir means shield. What you said was ‘May luck and happiness follow you and may you be a shield from misfortune.’" Unfortunately, "a shield" is a noun, not a verb, so it can't have a past tense. Also, Eragon wasn't using the active past tense, but the passive future imperative ("may you be shielded" is an imperative pertaining to something that is to happen, not something that has happened).
Dancing Bear: The first book was sold on the basis of having been written by a 15-year-old.
Designated Hero / Designated Villain: As you may have seen elsewhere on this page, a great many fans actually perceive Eragon as a villain and Galbatorix as an antihero.
Murtagh: even some of the anti-Eragon fans like him.
The latter part may be because some fans left the series at his Face-Heel Turn, since he was the Ensemble Dark Horse and it seemed like an attempt to get more fans behind Eragon.
Roran holds this position, too, largely due to many people finding his parts in Book 2 to be more enjoyable then Eragon's parts.
Carn from Brisingr and Inheritance is fairly popular, too.
Fridge Logic: Galbatorix uses the rules of the Ancient Language to force people to do things for what he thinks is the greater good. When Sloan (a his cousin Roran's traitorous father in law) shows up. Eragon tells Roran that Sloan dead. Then he uses the rules of the Ancient language and forces Sloan to never see his daughter again. All for the good of Roran's marriage, of course.
Follow the Leader: A rare positive example - alongside Harry Potter, it was one of those books that helped tell publishers that yes, young adults do in fact have the attention span to read long books, especially ones that span multiple installments.
Growing the Beard: Brisingr is considered by some readers to be an improvement over the first two books. Inheritance took the changes further.
Ho Yay: The books are worth reading for this alone. See the main page for more.
Internet Backdraft: Fans of the Inheritance trilogy have their hands full defending the object of their fandom from a gigantic number of anti-fans. Anti-fans have to defend their criticism from a gigantic number of fans.
Rooting for the Empire: Incredibly common. It doesn't help that the book concedes that most of the people living in The Empire are happy and at peace, giving the impression that if the Varden would just stop fighting everyone would be fine. And though the emperor is a douche, his evil actions all seem to be about fighting the Varden so, again, his rule would probably be much less tyrannical if the Varden didn't keep going at him. It doesn't help matters that the main character is widely considered to be a Designated Hero with a lot of Kick the Dog moments.
Strawman Has a Point: Galbatorix can be seen as this. While later books established him as being thoroughly evil and tyrannical, his depiction in early books left him looking pretty good for many readers. His rise to power (in which he won humanity's superiority over the elves and killed the all-powerful dragon riders) is portrayed as a Moral Event Horizon, and he wants to stomp out the urgals, a warlike species whose rite of passage is to find something, anything, and kill it. He's done plenty of unsavory things and isn't to be praised, but he's made humanity safe and superior, and even his enemies acknowledge that his batshit insanity doesn't touch most of his subjects. And he is the established power, with a clear-cut law, as opposed to the Varden, who will gladly accept you into their group provided you A.) follow your flawed and suicidal orders to the letter, and B.) be sure to always shower praise on Eragon, the elves, and your visionary leader, Nasuada. In the end it isn't so much that the Strawman Has A Point, but that the other side is so self-righteous and annoying the reader finds it hard to root for them.
They Just Didn't Care: No, the author himself put his all into his series. In this case it was the editor who was lazy. Aside from making sure that nothing was misspelled there are tons of minor and major continuity mistakes, Purple Prose abound, and somehow didn't notice that a sentence containing the words "descended upwards" doesn't make any sense.
The publishing company that picked up the series. Basically the CEO gave his kid a copy of the book, the kid said it was "the best book he’d ever read, that was written by a young adult" and instantly published the book as-is (and made sure it was released before the latest Harry Potterbook).
Villain Decay: Murtagh. When he is first seen in Eldest, he's sympathetic but his actions are well-justified and believable. But by Brisingr, he's decayed into Galbatorix's minion complete with an evil cackle.
Villain Has a Point: Galbatorix is of course an evil tyrant, but his concerns about how easily those with magic can manipulate and abuse those without it are entirely valid. Even after he is gone, Nasuada struggles with the exact same issue.
What an Idiot: Eragon. "Huh. That perfectly smooth, round rock seems to be squeaking. Do rocks usually do that? Weird. Oh well, it's probably nothing. It's definitely just a regular rock. I'll just leave it on the shelf and go to bed, and not tell anybody."
Dangerously Genre Savvy: Galbatorix, in Inheritance. He hijacks the magical language itself in the final battle such that only he can use it, effectively depowering nearly every other character. The only reason he lost was that Murtagh was not as loyal as he thought.
In Eragon, Eragon, Murtagh, and an unconscious Arya are accosted by some slavers, who try to collect the bounty on Arya's head. Although they are quickly dispersed when Eragon reveals his magical powers, Murtagh captures, disarms, and kills the leader of the slaver band. Eragon views this as unnecessarily cruel and vicious, even for an Asshole Victim. However, Murtagh's argument - that by letting them live, they are free to spread information throughout the Empire of the location of a Rider and a wanted elf princess - seems harsher but more pragmatic given the situation.
In Brisingr, Nasuada has Roran publicly flogged as punishment for insubordination despite his heroism in battle. It seems pretty harsh, but given her very delicate position as Varden leader and her importance in their alliance between the dwarves, the elves, the Surdans, and her own followers, anyone openly defying her leadership could be seen as a potential threat.
Magnificent Bastard: Galbatorix. By Inheritance, it's clear that his cunning and manipulation go much deeper than anyone would previously have guessed.
Arya shows disdain for human women, who she considers to be weak and helpless. She briefly wears a dress in Brisingr, and when Eragon comments on it, she says that she never really understood why humans insist on separating their men and women in these ways.
Subverted by Nasuada, who is never seen outside of a dress, thinks it's sketchy that Arya wears pants, and finances the war by selling fine lace.
Eragon at the end of the series. At around 16, he's facing complete isolation for years, having to explore a vast new continent that is extremely difficult to reach, and establish a new order of dragon riders there virtually by himself. He does not expect to see any of his loved ones alive again (which a certain prediction makes explicit), and has given up all thoughts of romance or pleasurable company. Kind of harsh for a band of grown men, let alone a single teenager.
King Orrin - after years of busting a gut for the Varden (in Eragon Orik flat out says: "The Varden couldn't exist without Orrin,"), living in terror that Galbatorix is going to roll over and crush his kingdom and enslave his people, and sheltering the Varden's noncombatants, he is completely supplanted in La Résistance by Nasuada, insulted by Roran and seems destined to spend the post-war period as a "second-fiddle" nation to the Empire. No wonder he takes to the drink.