I liked most
of City Of Bones, however when I got towards the end of the book I just found myself losing interest to the point where I ended up skim reading the rest of the pages.
The main thing that did it for me was the whole Clary/Jace being brother and sister that I found quite weird, especially considering the relationship they had throughout most of the book....how does no one else see something odd about that? I just felt like it was a bit of a let down to the rest of the story.
I'd say that the book was decent enough to make me want to see the movie when it comes out though, so it'll be interesting to see how it turns out.