School fantasy is often aimed at children, and it's very successful at hitting that market. It's much harder to appeal exclusively to adults, and that's where The Magicians shines. Rather than the typical twelve-year-old protagonist, it tells the story of a high-school student not yet aware of his powers. Quentin Coldwater is obsessed with fantasy books, an outcast, and somewhat depressed. When given the opportunity to study magic, he jumps on it, but quickly learns it’s not as fun as it seems. In The Magicians, spells are hard. Learning magic is tedious and requires background knowledge of language and history. Quentin finds himself frustrated at his progress, no longer the prodigy he used to be. From there, the book only gets darker. The antagonist has no mercy, magic can kill simply through accidents, and drug use is rife. Lev Grossman stands in stark defiance of convention, refusing to sugar-coat magic and creates a tense and compelling story as a result.
Books in The Magicians Series (2)
You might want to give Susan Clarke's Jonathan Strange & Mr. Norrell a read. Like Lev Grossman's The Magicians, it's a story about magic in a world that supposedly has no magic. Both novels veer from the usual fantasy conventions, weighing in as more than just "fantasy." I like to call these "literary fantasy." This novel, however, heralds back to the Victorian era and features a more conventional sort of story (that borrows heavily from the likes of a Jane Austen novel in language an description) and is NOT a postmodern take on the fantasy genre that The Magicians is.
For another novel about Magicians in training, you might like The Night Circus. It's about two young magicians locked in deadly conflict trying to outperform the other who are both part of a magical circus. It's a rich and intoxicating read, most decidedly literary and one of the best fantasy books of 2011.
Harry Potter. Yes, if you like The Magicians, read Harry Potter the titular character who is deconstructed by Grossman and reformed into a far more complex and troubled and fallible version as the character Quinton.
If we are going to follow that rabbit down the rabbit hole into the dark and murky literary past, seeking the origin of boy-goes-to-magic school to become a wizard, we might as well get to one of the sources. If Potter made it a pop culture thing, then Ursula Le Guine helped bring it alive like no other author. Yes, I'm talking about The Wizard of Earthsea. Before there was Harry Potter, there was Ged.
Ocean at the End of the Lane by Neil Gaimen. One thing I love about The Magicians is it moves the simpler children's fiction into the adult realm with an adult perspective. It's Narnia for grown-ups.One book about that perfectly captures the child realm but transforms it for adults is Gaimen's Ocean at the End of the Lane. Thematically, Gaimen does the same thing as Grossman. While both works are completely different in scope and plot, they do take a child's perspective but remake it for an adult which changes it.
The Secret History by Donna Tart. Not specifically fantasy per say, but the writing and tone, and characterization are somewhat similar. A young group of students at a college discover another way to think about their life and the ramifications of this change everything about how they live.
Anathem by Neal Stephenson. A science fiction story about a young boy who's a sort of monk and finds out the wider world is a complicated place.
The Magicians alludes to a number of popular fantasy classics. Alice in Wonderland is one such work and The Chronicles of Narnia. In fact, if you dig down a bit, The Magican books are a postmodern version of Narnia with the friendly animals revealed to be monsters.