I personally believe that if a book has an interesting idea the Lexile Level doesn't matter, in literature not necessarily technical information. That is as long as it is above 5th or 6th grade (I read DS9's books). I have found that most things I read today I could have read as a 6th grader. (I did attempt War and Peace and gave up. I attempted to read it a couple of years ago and realized I was right the first time.)And often the higher lexile levels are artifacts of the formality/archaic nature of the language used, case in point Pride and Prejudice.
As far as the Hunger Games, I find that dystopian societies make for interesting reading and discussions. The depth of understanding of the concepts is not limited by the reading level. I find no redeeming value in DOAWK though. DS has been reading DOAWK books since K and this year I am banning them.
