Also I liked the first two books, and the third was good too, but it seemed like it was full of things that didn't need to be there. It was almost as if Eragon was doing a bunch of 'side quests' instead of completing the main storyline like he should.
My guess is that it was the author introducing a few plot elements, so when he pulled them out of no where to fight Galbatorix, they'd be a Chekhov's Gun rather than just a plan old Dues Ex Machina.
I read the first two books - which I loved - when I was at boarding school (a lot of free time) and the third a couple of years later when it came out. I enjoyed it significantly less, probably due to my tastes changing, so I'm not holding high hopes for the fourth, but I'll probably read it nonetheless.