I would have to throw in a vote for predictability. Too many people think that just because you can pice together a plot, that it will be interesting. Someone has already done your plot, so you had better do it well.
Now that’s showing, not telling!
As a writer, I particularly hate reading things that I have to correct in my own work: overuse of adverbs, and excessive uses of, ‘‘he said/she laughed/the goat mumbled.’’ I do that shit all the time, but I correct it before it sees the light of day and so should others.
On the other hand, my grandest pet peeve of all is probably my greatest strength in writing: dialog. Nothing will make me close a book faster than unrealistic dialog.
I also hate stereotypes and characters who are too ‘‘clean’’, such as every male ever written in every chick-lit novel ever. Blaaarg. Show me a guy who’s bitchy and moody and downright irritating. Show me a woman who’s a neurotic mess. When they fight, let it get dirty.
To summarize: I want to see people talk like people talk, and I want to see people act like people act. Is that too much to ask?
I feel a little better now. Some people I’ve shown my work to have complained because I didn’t physically describe my characters physically(build, eye color, hair color, etc). My response is usally that I couldn’t really tell you what they look like despite a general idea. In books where someone takes the time to describe their characters physically, I usally end up glossing over it and completely forgetting anyway, unless the character has a very particular characteristic. If there’s picture of the character somewhere(or if there was a movie version) that becomes the defacto picture in my mind.
I’m all for good character development, but I don’t consider their looks to really matter, particulary when it comes to writing. Unless the looks are important to the character or the plot or the atmosphere. Maybe it’s the books I grew up reading.
I’m particularly sensitive to artificial stupidity at this point. I hate it when the entire plot hinges on the main characters getting a sudden case of the stupids just to move the plot forward.
Some of my pet peeves:
-Plot threads that really don’t seem to go anywhere. I’m reading House of Leaves right now and while I really like the main story, Johnnys constant rambling about his life in the footnotes is really getting on my nerves because I can’t for the life of me see how it has anything at all to do with the main story. I’m trying to shake the feeling the author had two completely different books that he tried to shoehorn into one, or he’s just trying to pad the story.
-Writing where the author seems to forget exactly what he’s trying to say or somehow manages to bury his story under a bunch of much less interesting things. The Amber Spyglass by Pullman. Towards the end
There a huge battle between Heaven and a mutitude of different earths. Not that you’d know that for sure because Pullman seems to forget it’s going on and buries it in the text of a whole bunch of other things going on. When you keep going back and rereading the same few pages over and over to figure out if you missed anything, the author is failing at his job
Or a character just being unbelievable stupid to begin with. C.S. Lewis did this in “That Hideous Strength” with a main character who figures out the organization he’s looking for a job with is…evil. His big concern continues to be “Will I have a proper job title and a paycheck?” even when they threaten to frame him with murder if he doesn’t join up. I half wanted them to go ahead and kill him, because he really was too stupid to live.
If it had been played for comedy, I probably would have enjoyed it. But no, it’s played dreadfully serious and the character feels like a strawman.
A very narrow variety of this ticks me off from the Lord God King of all miserable hacks, James Patterson. (I swear I only know this because of audio-books, for which I have a much lower standard.)
James Patterson has never in his entire life (to my knowledge) bothered to describe one of his characters; by some happy accident, they all happen to look like some figure from popular culture: “Lila looked like Jodie Foster, only with blond hair.” Repeat, for every single character.
They should make drinking games for books.
Not only that, but they’d be speaking in Latin anyway! Why on earth is “contio” the only word not implicitly translated in that sentence, and why would they repeat themselves?
In dialogue writing where it’s understood that the words are being translated to the language of the rest of the narrative for the convenience of the reader, this is an irritatingly common, blindingly stupid, and completely unforgivable conceit. I just want to track down writers who do this and smack them with a carp until they apologize.
Oh lord, yes. I find present tense narration to be extremely distracting somehow, especially in the first person. It just feels like too much of a narrative implausibility.
In general I very much agree: there is almost never any reason to describe a character’s appearance in every detail, and, IMHO, there’s nothing wrong at all with completely refraining from any physical description of your characters if it actually isn’t relevant. It does make sense to focus on the details that are actually important (such as they are), especially when writing experiential description from the point of view of another character – i.e., in the circumstances, what aspects of appearance would this other character actually notice? Usually this will be limited to general appearance, which is best anyway: the reader should be able to fill in the rest.
Anything much beyond that is hack writing, as is burdening your characters with an excess of physical characteristics that you feel the need to describe completely, as Maiira mentioned earlier.
There is a special place in hell reserved for writers who liken the appearance of their characters to contemporary celebrities. 
I really hate it when the last page of a book is missing.
Here’s another one: incompetent metaphors. There are many out there, but the worst I have ever seen, which I mentioned a few years ago, engendered violent tome-discarding that threatened the paintwork in my living room. It was the following attempt at a simile:
“Dust moved in the air, like particles in Brownian motion.”
You ignorant penis, dust moving in the air is particles in Brownian motion. No simile for you!
I walked into the Cafe Society room and noticed a loaded Beretta on the end table. I wondered to myself, “Why in the world would there be a loaded gun in the Cafe Society room?” I dismissed it, and walked into the What aspect of bad writing bothers you most? conversation. I nodded my head along with complaints about clunky exposition and bad dialogue. I was about to chime in with my two cents, saying that I’m not a big fan of glaringly obvious foreshadowing when – BAM! – I took one to the kidneys by that damned Beretta.
(It’s Chekhov’s gun… arrest him for the shooting!)
A plague of chick lit: To show how funnyneuroticlikeablesassyselfconscious the main character is, authors will write the main character in the first-person perspective, and proceed to narrate her every thought, right down to the mundane. Let’s have a little restraint, hmm? I don’t need to know every single thought not relevent to the story. You’re not making it real, you’re making it obnoxious.
I read the first couple of SPQR mysteries, by John Maddox Roberts, and there was always a convenient foreigner sitting around who needed to have Roman customs explained to him. I think it takes a lot of skill to convey details of a historical setting without lecturing the reader. I felt lectured in the SPQR books, but not so much with Lindsey Davis or Steven Saylor.
I really dislike cliffhangers, particularly when they are deliberately contrived in order to induce you to buy the next book. Rachel Caine is terrible about this.
One would hope that as a book progresses, the bad writing would get better. However, often, the writer becomes weary or bored and the writing actually gets worse.
Wow.
Did NOT see that coming.
If you are reading a Strattemeyer Syndicate book (Nancy Drew, Tom Swift) the author is contractually obligated to do exactly this at the end of every chapter. My favorite is a Nancy Drew book where she is on an ocean liner, mid-ocean, nothing happening - when a giant meteorite plunges into the ocean right near the ship. Nothing to do with the plot, no impact, just a false bit of suspense.
Some others:
Multiple adjective. The tan, thin, stupid boy.
Authors describing characters by having them look into the mirror. “Wow, I never realized I had black hair!”
The stupid character has already been mentioned. I also dislike the author ignoring the logical consequences of a major event. New York has been destroyed by a terrorist bomb, but the CIA can only spare master spy Maxwell Smart to bring in the terrorist before he strikes again.
The strange affliction that seems to affect a lot of published writers where all the characters manage to have exactly the same voice. Characters share common turns of phrase, bases of metaphor, styles of speech, even when they’re otherwise quite different. Your erudite old philosophy professor speaks exactly the same as a teenage girl. Possibly I hate this one more because I find it hard to avoid in my own writing, but at least i’m not published.
My other big annoyance is taking a potshot at some other work, but having that problem as well. If you’re going to make fun, fair enough, but you’d damn well better have avoided that problem yourself.
Yes, many times yes. In a thread a few years ago here on SMDB about The DaVinci Code, someone called it ‘Artificial Stupidity’ (of which, natch, TDC had a ton). Author uses dialogue (usually, although it can be internal dialogue) to explain a topic to the reader - without understanding that the dialogue would never take place in reality. Totally takes me out of the book.
Give me the author who has two paramedics talking and saying something like “yeah, had a GSW come in yesterday” and who NEVER explains that ‘GSW’ is shorthand for Gunshot Wound. Let the dynamics of the situation explain it.
Bad author would have one paramedic say “GSW? Do you mean Gunshot Wound?”
AMEN!
I’ll add to that my favorite peeve: Inappropriate use of the apostrophe S ('s), or omission of same when it’s actually needed.
I had to stop reading Anne Rice for using “preternatural” every other paragraph and Stephen King for all of the, “And he/she was never seen again,” “he/she was never seen in recognizable form again.”