Everyone has little things in books that bug them, ranging in reaction from minor irritation to a full-on “if this is there I will stop reading immediately.” Here are some of mine, in no particular order:

• A man falling in love with a prostitute (a.k.a. the hooker with the heart of gold). It’s been done, people. Done to death.
• Conflict/drama caused entirely by people not telling each other things. This drives me insane. Yes, I get that people have secrets, but too often characters hold back because (1) they have a martyrdom complex and don’t want to burden anyone with their problems, or (2) they think people just wouldn’t understand, and don’t even give them the chance to decide. It’s dumb, and it’s even worse when it’s the entire reason pretty much everything in the plot happens. If I can read a book and think “if they’d only told each other everything from the start, we could have avoided pretty much the entire story,” it really irritates me, and it’s a sign of weak writing.
• Large amounts of foreign language. I was going to say it only bugs me when it’s not translated, but it also bothers me when people say things in a foreign language and it’s immediately translated into English. The occasional word is fine, but paragraphs or entire conversations get very tiresome. It’s a great word-padding trick for NaNoWriMo but I’d rather it were left out of published novels.
• Conversations that are described instead of printed. Jane Austen was particularly bad about this, but she’s far from the only offender. The only exception to this is if the information would be a repeat of what the reader already knows.
• Stories that don’t end. Now, I don’t need all the loose ends to be tied up, but I do need a story to have a satisfying (though not necessarily happy) ending. When it just stops and it’s left totally up to the reader to decide what happens (such as in The Crimson Petal and the White by Michel Faber), I feel like I’ve completely wasted my time reading it. If I wanted to write my own ending, I would have written my own story. Finish what you start!
• Authors that don’t do basic research. I’m not talking about little anachronisms in historical fiction; I mean truly basic information that anyone with even a passing acquaintance with the topic would know. James Patterson is a good example. He sets many of his novels in the DC metro area (which happens to be where I live) and then makes such glaring mistakes as inventing a mysterious city in Virginia called Church Falls and asserting that locals refer to the Smithsonian Institution as “The Smithy”. (We don’t. Seriously, nobody says that.) If you want to make up stuff, don’t set it in a real place. All you’re doing is irritating the natives.

I’m sure there are more I’m not thinking of. What are your pet peeves in books?