Dunno if it's suitable for the average teenager - I enjoyed reaging it, tho. "Gödel, Escher, Bach: An Eternal Golden Braid" by Douglas R. Hofstadter. Heavy stuff but cruely interesting. Can also recommend everything from Stephen King and/or Karin Slaughter. Those are partly pretty brutal thrillers, so maybe not so teenager-ish but great books anyway! If you're into that kind of stuff. Pretty good book, seriously. Read it a few weeks ago. Is there an english version to that book?