It's so frustrating when a main character is passive, boring and dragging the whole book down with them. The novel I'm reading now never shows the resolution of a conflict. The girl runs away and her protector dispatches the villain off camera. Argh! Why is she even the main character? I'd rather be viewing events through his eyes.
In Nancy Kress's book "Characters, Emotion and Viewpoint", she says you have to decide who you're going to tell the story through. I dismissed her advice at first--I start with a great idea and a main character and I can't *gasp* change it!--but I've seen many instances where it would've been better to axe the main and use the sidekick or the opponent as the focus of the story.
The main protagonist should drive events, make the choices that affect how everything turns out, and preferably be strong. In Stephen King's "On Writing" he talks about how Carrie was never his favorite character because she was so meek and passive most of the time. It was a very successful book, but I don't think it would have been if she hadn't transformed into the evil, scary, exactor-of-vengeance she became at the end. Nowadays, most people's attention spans are shorter (as we are overwhelmed with books, TV and movie choices) and I doubt few people want to wait until the end before the character is interesting. I know I've decided to never buy another book by the author I'm reading now, no matter how it turns out. There's been too much agony along the way.
My feelings on this subject have affected my own writing lately. I've noted where a character behaves more passively than I'd like. I also found one instance where my main was saved by somebody else! That won't do. I'm now rewriting it so, even though people who care about him are trying to help, they can't, and he has to find a way to get himself out of hot water. I think it will make for a more engaging story, so it's worth the effort.
What about you? What really annoys you in books? Do you often find a secondary character more interesting than the main? If you're a writer, have you ever thought about making someone else the main protagonist?