- Formatting - No space between paragraphs and no indents, creating an almost-wall-of-text.
- Homonym fails - self-explanatory
- Stupid words for various body parts
- Unrealistic or stilted dialog - real people aren't grammatically perfect, and they use contractions.
- Contrived lack of communication between characters because of something stupid for the purpose of adding tension - "But I was afraid if you knew I was allergic to cats you wouldn't love me anymore!" At least TRY to give the character a valid, realistic reason for hiding something, ya know?
- Overplayed sympathy for the devil #1 - it's okay to make the bad guy be human and have weaknesses, but if I like him better than the good guy by the time the good guy wins, I'll be left confused, irritable and unsatisfied.
- Overplayed sympathy for the devil #2 - If you're going to reveal that the bad guy is actually the good guy, try not to give it away in the first few pages, eh?
- Lopsided love triangles - The guy who wins the girl should have more redeeming qualities than the guy who loses.
- Showing off the research - You researched the book you wrote. Good for you, but I don't need 5 paragraphs describing something that has no relevance to the story just so you can justify your extensive research.
- Glaring geography fails - like the lovers watching the sunset over the ocean on the East Coast of the US.
- Glaring sex fails - She's petite, he's a giant. I'm 5'3" and I once dated a guy who was 6'7" - I KNOW what works and what doesn't.
That's all I can think of right now.