The Magicians by Lev Grossman

>At age 17, Quentin has gone through the Brooklyn school system, sorted and separated by smarts into the “nerdiest of the nerds” group, and is unenthusiastically headed for Princeton when he finds himself taking an entrance exam for an entirely different kind of post-secondary education—at a school of magic.
A secret lover of the children’s series about the magical land of Fillory (a Narnia-like place that human children can only find at the most unexpected times), Quentin knows all the stories by heart but never expected to find real magic existing in the world, hidden from all but the most gifted and singled-out of humans.
The Magicians by Lev Grossman (author of The Codex) is the perfect novel for anyone who, like Quentin, ever wished as a child that magic was real and is, still, maybe even a little disappointed not to have been the one selected to go through the looking-glass, to travel to the land inside the wardrobe, or to find the Indian in the cupboard. But be forewarned. The Magicians is no light-hearted frolic into fantasy, a la Terry Pratchett or Jasper Fforde. Talented Quentin Coldwater has a depressive streak that even his wildest dream coming true doesn’t erase, and so does this novel.
Readers of Jonathan Strange and Mr. Norrell by Susanna Clarke should enjoy this completely different take on magicians.