There were always also science fiction for the nerds who would become the rocket scientists and digital gurus of our time and superhero comic books for the less ambitious.
More and more now, though, I see that the more popular books are escapism -- fantasy, witchcraft, werecreatures and vampires, dystopian worlds where heroines and heroes are made, "regular joes" who turn out to be His Majesty or descended from Apollo or Merlin. I see many books written today about disabilities, but except for J.R. Polacio's Wonder, none have become incredibly successful and sought-after. True, in the Southwest -- Arizona to be specific, Dusti Bowling's Insignificant Events in the Life of a Cactus was recognized for its award-winning story about kids that don't fit in -- a girl born with no arms, a boy with Tourette's Syndrome and a very obese boy -- just being normal kids. However, while Lynne Kelly Song for a Whale, about a 12-year-old deaf girl who's wild about science in general and old radios in particular finding an affinity with a lonely whale, is an Indienext Pick, Books on First has not exactly been stormed at the door with purchasers. Nor is Song for a Whale the only recent book about deaf children being amazingly smart but misunderstood. (Personally, I think Iris is a bit of a pill, but maybe that's the result of people treating her special, when she just wants to be treated like a normal student (as well as have everyone learn real sign language).
Another type of book littered with juveniles is the coming-of-age, but these don't seem to be children's books, but rather nostalgic memoir-based books for adult reading. I cite Caitlin Moran's How to Build a Girl (remember daisy wheel printers?) and Jason Rekulak's The Impossible Fortress which seems to throw teen pregnancy and bullying along with programming with FORTRAN on Commodore 64s.