Cassie: We're all just worried that this mission will, you know, be a little rough on you, Marco. Ax: Yes. Also that the fact that this mission involves your mother will damage your judgement and cause you to make unwise decisions that might result in all of our deaths.
An Outcast in Another World: Elder Alessia when explaining to Rob that his aversion to killing people will get him killed. It's even worse coming from her, as she's someone who outwardly dislikes him, meaning that she wouldn't be offering advice at all unless it was for a very important subject that he absolutely needed to know about.
The Change Room: Eliza is given to saying whatever's on her mind, even when it's insulting to others and shocking otherwise. Andrew, her husband, feels embarrassed but curious or amused too about this.
City Of Truth: The main character lives in a city in which everyone has been psychologically conditioned to be unable to lie at all. The book opens with him enjoying driving his new Plymouth Adequate (which replaced his old Honda Cheap) on his way to pick up his son who has been unexpectedly taken ill at Camp Ditch the Kids. But there is a dark quandary waiting for them both, for it turns out that his son has contracted a rare disease that has only ever been cured with the placebo effect.
The Curious Incident of the Dog in the Night-time: Christopher, the main character, is autistic and can't lie. He explains this by saying that if he said he ate Corn Flakes for breakfast when in fact he had Cheerios, he would be thinking about something that hadn't happened; but then he'd think of other things that hadn't happened, for example, that there hadn't been a scuba diver at the table, or an elephant, and so on, and would get so wrapped up in thinking about what didn't happen that he'd forget the lie he'd told in the first place. It goes so far that he considers anything that didn't really happen a lie, even fiction (the one exception is Sherlock Holmes novels, which he enjoys). It's not just lying, either — he can't pick up on social cues, so he doesn't know what's appropriate to say and what isn't, and so has to be told not to say that one of his classmates is so stupid he would eat pound notes, coins, and his own poop. This is Truth in Television for many people with autism (though the opposite can also be true).
DFZ: After Opal and her father have mostly reconciled, they have to dress up as part of a plan. Yong bluntly tells Opal exactly how the dress he got her covers up all her physical flaws. He doesn't understand why she could possibly be upset; doesn't she want to correct her flaws?
Opal: Haven't you ever heard of tact? Yong: Tact is for enemies. Family deserves the truth.
Diary of a Wimpy Kid: Rodrick Rules: Greg makes a promise to always be truthful to his mom. Unfortunately, he doesn't quite grasp the distinction between not lying and bluntly stating his full thoughts on a given subject with or without prompting. This leads to him saying insensitive things like that a short boy can never become a basketball player or that Rowley's grandfather may die before ever having another birthday. Greg is also this in general when it comes to his opinions. His grandpa is even bigger, as he will just straight up say who his favorite grandchild is.
Small Gods: Brutha isn't so much incapable of lying as he is unable to understand the concept. Given his perfect memory (the first thing he remembers is a bright light followed by someone hitting him), he doesn't get why people would go around saying things that didn't happen.
Maskerade: The Ghost specifically Walter has this as a predominant feature of his personality. He isn't trying to be cruel, but he can be viciously accurate — as Agnes finds out when, while imitating Christine under cover of darkness to find out his game (and his offer to teach "Christine") and pulling a …But He Sounds Handsome. The reply is that this is true, but musical ability can be trained (though he later concedes that Christine will never be quite as good). The difference in looks (slim, pretty, blonde vs Brawn Hilda) and grace, however, can't.
This is one of the responsibilities of Professor John Hix from Unseen University's Department of Necroman... er, that is, Department of Post-Mortem Communications. As UU's resident "evil" wizard, he is expected to make tasteless remarks anyway and so it falls to him to say the things that no one else wants to say but which must be said regardless.
Disgaea Novels: Ozonne. When Laharl asks her what she thinks of him the first time they meet, she says she thinks he is "a weak and incompetent brat". Later, after she falls for him, she asks him casually to marry her.
Greek Ninja: Sasha never hesitates to tell the truth even when it's devastating.
Gulliver's Travels: The Houyhnhnms are completely honest by nature, to the extent that their language has no word for a lie.
Luna Lovegood is known for being painfully honest. Most of the time, no one really minds because the things she says about others aren't very critical, and she reacts with a confused stare instead of an argument when people disagree with her. Her honesty disturbs Harry when she talks about her own life, namely that everyone considers her crazy and picks on her, and she doesn't have any friends.
When Firenze becomes the new Divination teacher in Harry Potter and the Order of the Phoenix, he concedes that Trelawney may or may not be a seer but he is brutally frank about what he thinks of her methods.
Parvati Patil: Professor Trelawney did astrology with us! Mars causes accidents and burns and things like that, and when it makes an angle to Saturn, like now, that means people need to be extra careful when handling hot things— Firenze: [calmly] That is human nonsense.
In the sixth book, Dumbledore straight up tells Harry he thinks Divination is a bunch of BS and that Professor Trelawney is a fraud. He only keeps it on the curriculum because parents want it taught and to keep her safe from Voldemort. (That said, she has made some actual prophecies (which is why she's in danger); it's just the divination methods she teaches in class that are considered useless.)
Beren and Lúthien: Beren tells Thingol to his face that he is disrespecting his daughter, and that obtaining the Silmaril is a bad idea. Given that Thingol is not only the most politically powerful ruler in Beleriand but also a several thousand years old light-elf married to a literal angel, this is a pretty gutsy move. Beren is ultimately correct, however.
The Lord of the Rings: When Faramir rhetorically asks his father if he wishes that Faramir had died instead of his older brother Boromir, Denethor replies with "Certainly I wish it, for Boromir was loyal to me, and no wizard's pupil." Faramir replies with an equally blunt reminder that Denethor was ultimately responsible for Boromir's death since he overrode Faramir's desire that he be the one to go to the meeting in Rivendell and sent Boromir instead.
My Fair Godmother: The main character tells her sister that she has to go back in time to rescue the guy who disappeared from his home in the present. It's safe to say that her sister didn't believe her. However, it might be inverted because she cannot lie without having to spit up a frog or something.
No More Dead Dogs: Wallace Wallace practices this because his father told him about fighting in the Vietnam conflict, making his son very proud of him. Wallace is disappointed to find out that his father was lying about the whole thing (he was too young to have even been in the army during the Vietnam conflict.) His incredibly harsh but entirely honest book report on "Old Shep,My Pal" leads to his English teacher (who's directing the school play of the book) to believe that he never read it.
Mr. Darcy's tendency to share his honest opinions (because he's rich, proud, and socially awkward) ends up giving him a bad reputation in Longbourn, particularly with Elizabeth Bennet, and breaks up the romance between his best friend and Elizabeth's sister. Even when trying to propose marriage to Elizabeth, he ends up insulting her and her family. Thankfully, he takes a level in kindness and humility by the novel's end.
Darcy: You must allow me to tell you how ardently I admire and love you. In declaring myself thus I'm fully aware that I will be going expressly against the wishes of my family, my friends, and, I hardly need add, my own better judgement.
Elizabeth herself has moments of this, particularly when turning down Darcy's first proposal. Downplayed, however, since she has significantly more tact and wit than the first two examples, and tends to be blunt only when speaking truth to foolishness or when other niceties have failed.
Elizabeth: I hope I never ridicule what is wise or good. Follies and nonsense, whims and inconsistencies do divert me, I own, and I laugh at them whenever I can.
Ravelling Wrath: Rinn rarely holds back from saying what's on her mind – especially to Morrow. After Morrow falls too far under the Seeking God's influence and starts attacking everyone with his magic powers, and the others have to work together to stop him,
Morrow: I did something wrong... didn't I? I sized him up, deciding how to answer that. Alchemist would probably have wanted me to soften the truth. But if I did that, I would feel like I was bullshitting him. And even if I did, he would probably just keep digging until he got the truth out of me. "You pretty much did," I said. "You fucked up real bad, and you hurt all three of us. And it could've been a lot worse if we hadn't all worked together to save you. But-" I grabbed his shoulder and made him look at me. "-it's over now. You don't have to hurt anyone anymore."
Rebecca: Maxim considers his sister Beatrice's direct and forthright nature to be her best quality, telling his new wife that if Beatrice dislikes someone, she tells them so, right to their face. Said wife, who is utterly terrified of meeting her upper-class in-laws, doesn't feel the least bit better upon hearing this description and wonders if there isn't some virtue in dishonesty. Luckily, though, Beatrice is just as forthcoming with her praise as her criticism, and when she meets Maxim's new bride, she immediately likes her and isn't shy about saying as much.
"Rejection Slips": "Gruff", the second letter, is a poem that uses short rhyming couplets to declare the submission is terrible, and that anything else can and should be sent instead.
Mary breaks Colin out of being a hypochondriac Spoiled Brat by bluntly telling him that he's a horrible person to be around and that there's absolutely nothing wrong with his back (he thinks that he's a hunchback).
Martha, who is not used to working for the gentry, frequently tells Mary (who still expects help getting dressed at age nine) that Martha's 4-year-old sister can look after herself better. She also compares wealthy kids, who are taken for walks by a nurse rather than playing on their own, to puppies.
Sandor Clegane is an embittered Straw Nihilist who's perfectly willing to shatter people's fancy delusions into powder.
Ser Davos Seaworth is a common smuggler raised above his station and so loyal to his king that he makes a point of avoiding the ass-kissing behavior that others display. His boss appreciates this so much he's repeatedly promoted for it without asking, and his advice is more valued than any of the other advisors'.
Stannis Baratheon, Davos's boss, seems incapable of sparing anyone's feelings even if he tries. His most heartwarming gestures still crash into the recipients with unpleasant truths attached.
Tyrion Lannister is adept at using this for his own purposes. Especially noticeable in his treatment of Jon Snow, who incidentally is one of the few people Tyrion calls 'friend'. One of the things he likes about The Dragon Bronn is the latter's lack of pretension, and tendency to be completely open about what he thinks of their Crapsack World. On the other hand, when Tyrion makes the mistake of Calling the Old Man Out and demanding to know why he is denied his rightful inheritance, Lord Tywin responds with a truly vicious (and totally undeserved) "The Reason You Suck" Speech, spelling out everything he hates about his dwarf son.
Bronn is also a dab hand at this. The best example is this one: he warns Tyrion upfront that, should a better offer come along, he will give him a chance to meet or improve on it. If that's not possible, he's out the door and on to the next job. And, he does exactly that: The Power of Friendship doesn't get a look in. He's a sellsword. If he doesn't live up to his word, he's likely to be dead.
Uprooted: Alosha the Witch is very old, very wise, and utterly blunt when talking to Agnieszka — even when saying that she wanted Agnieszka's dearest friend executed to protect The Needs of the Many or telling Agnieszka that she accidentally started a war. She also bluntly tells Agnieszka that she's far too powerful for her age and needs to grow up fast so that her innocent mistakes won't cost lives.
Vampire Academy: Rose Hathaway isn't shy to speak her mind, regardless of how inappropriate the situation.
Village Tales: The clergy don't mince words. The Duke is polite only tactically and on rare occasions. The GP is noted for such remarks as "Of course you're unwell, you're fat! Digging your grave with a fork and your teeth!" Lady Crispin is fraffly plain-spoken. It would be hard to find anyone who wasn't weapons-grade blunt. Gossip is carefully kept from the ears of those who'd be hurt by it, but if something is said, it's not sugar-coated. (Truth in Television insofar as country folk tend to bluntness and the working and upper classes in the UK consider indirection and politesse a middle-class thing.)
Warrior Cats: Dawn of the Clans: Wind Runner does this for Bumble. While the other cats are wondering whether Bumble should join them or not, Wind Runner bluntly tells her that she can't because she doesn't know the ways of a wild cat.
The Winnie Years: When Sandra finds out about Winnie badmouthing Dinah in Twelve, she is brutally honest to Winnie. When Winnie says, "I'm an awful human being," Sandra says "Pretty much."
