(in a 'top ten' format...we all love that format really)
7. Brilliant AND Beautiful protagonists: why is it that the main character who's, for example, a forensic pathologist, has to actually be a BRILLIANT forensic pathologist? Not only that of course, he (or she) is stunningly attractive too, and of course incredibly funny and quick with the sassy comebacks. Oh...and yes, able to trade blows with the bad guy's henchmen, AND speak a second language fluently at a very convenient moment in the story. One thing that's guaranteed to have me tossing a book across my room is a SUPERhero. Gimme a regular guy who's just okay at his job, makes mistakes, doesn't fall into bed with every incidental character of the opposite sex, and you know...just looks pretty average.
Really ticks me off - characters like that. Crappy 2d hero stereo-types like that are why I never got any further than chapter 5 of The Da Vinci Code.