Good 8th grade level reading books?

First off, I need to say I moved to America through relocation and I learned there from K through 6th grade. In 6th grade I was a honors English student, and I mostly made A's and B's. I have one problem with reading: I can't stand slow written writing styles. Which means styles like what Mark Twain has to offer really bore me. I like fantasy, sci-fi, dark comedy, action, suspense (though not horror, I can't stand that), and light drama (like The Perks of Being a Wallflower). Also, I can't bear books that graphically described bodies. Just the first murder in The Da Vinchi Code almost kept me up all night.