Some books have ended up being memorable for me due to how ridiculous, disappointing and/or frustrating I found them. These are the most prominent examples. I read each one 2-7 years ago, so the following are not in-depth reviews.
Divergent by Veronica Roth
I decided to read the Divergent trilogy because of the cool titles, which was a mistake. The titles are the only cool aspect of this poorly constructed Hunger Games ripoff, which suffers from many common flaws of YA fiction (bland protagonist, lame romance subplot, weak worldbuilding). By the end of the first book I was too bored and apathetic to read the next two. This guy has admirably struggled through all 3 books, and explains better than I could why the series sucks.
Mindwalker by A.J. Steiger
This is yet another YA dystopia, about a world where scientists can remove traumatic memories. The protagonist is one such scientist, and the other major character is a guy who is so mentally scarred that curing him is considered too dangerous.
The main problem I had with this book was the romance between these two characters. It's an instance of a particularly irritating trope of YA fiction, where the supposedly intelligent and level-headed protagonist forgoes their better judgement to pursue a relationship with some complicated unstable individual (a more general version of the 'good girl, bad boy' trope, which I hate). The romance wasn't needed to advance the plot, as the protagonist had other motives for helping the guy.
YA nonsense aside, a small detail I found cool about this book was that the protagonist had the same name as her father (also a scientist), making her a Jr. Female Jr.'s existing in the book's society is rather neat.
The Humans by Matt Haig
This book wasn't 'dumb' as such, but it really rubbed me the wrong way. The protagonist, a member of a technologically advanced alien race, has been ordered by his leaders to kill a human mathematician who has proved the Riemann hypothesis, destroy his proof, and kill everyone who might have known about it. They want this done because they believe that the human race is not intelligent enough to use the newfound mathematical knowledge appropriately.
The book starts with the protagonist having followed his first order. He has now taken the form of his victim in order to start living in his place, a measure to prevent suspicion. Everyone is fooled by the disguise and believes that his odd behaviour, caused by him knowing nothing about humans, is due to the mathematician suffering a mental breakdown. After finding the Riemann hypothesis proof and deleting all traces of it, the protagonist starts assimilating into human society and appreciating humans and their creations, such as classical music and peanut butter.
Which is nice, I guess, but I couldn't get over the fact that the protagonist killed an innocent man, destroyed the poor guy's life's work, and stole his identity, deceiving his family and colleagues. Sure, he was following orders and thought he was serving the greater good, but even after he decides to stop obeying his leaders and cuts contact with them, he continues to use his victim's identity¹ and doesn't seem to regret his previous actions. He probably could have reconstructed the proof, but he doesn't.
Many of the events that are portrayed as wholesome are really just the protagonist acting selfishly (mmmm peanut butter). He even has sex with the mathematician's wife. He cucks the guy he murdered, while usurping his identity. I can't decide whether that or destroying a proof of the Riemann hypothesis is a more heinous crime. He does some good deeds later on, like preventing the mathematician's son from attempting suicide and stopping another alien from killing more people, but I can't bring myself to believe that that makes up for everything else.
Every opinion I've seen online about this book (reviews etc.) praises it for being funny and heartwarming. Did I miss something? How is this story anything other than disturbing skinwalker nightmare shit? If there had been some twist, say, the protagonist is actually the mathematician and he is recovering from a psychotic break which has caused him to believe that he's an alien, then I would agree with those reviews. (That version makes infinitely more sense to me, and would have been far superior.) Perhaps I wasn't supposed to take it so seriously, but given the themes, how was I not?
This book would only make sense to me if it was intended as psychological horror and mislabelled as quirky and wholesome. But that's not the case. What the hell?
¹One can argue that he had no choice because it would have been traumatic for the other characters to to discover the truth. They might not have been able to even comprehend it. Jesus Christ, what an irreparably horrible situation.
Vox by Christina Dalcher
This novel is set in a dystopia where all females are limited to 100 spoken words per day and prohibited from all other forms of verbal communication. This is an interesting premise and makes for some memorable moments, such as a scene where the protagonist is trying to stop her 6-year-old daughter from talking in her sleep, and another scene where her daughter comes home proud that she hasn't spoken a single word at school.
Unfortunately, the book turns from a decent Handmaid's Tale clone into a corny over-the-top thriller very quickly. I soon got bored and dropped it, partially because of this underwhelming development, but mostly because I found the protagonist aggravatingly unrelatable. She's supposed to be a top scientist but doesn't act very nobly or rationally. I couldn't really root for her, especially after she cheated on her husband and continued to lust after the other guy after ending the affair. As far as I could tell, her husband didn't deserve that; he did nothing wrong other than be less attractive and charismatic than the other guy.