I just finished the Mediator series by Meg Cabot. It's a young adult series, and while I got through them all pretty quickly, and enjoyed reading them, by the end I was extremely annoyed with the main character. It was to the point where I didn't even like her anymore.
I think it may just be the young adult genre. I had the same problem with the Twilight books that most everyone else seemed to love. I just couldn't relate, and got tired of the whining and silliness.