If you're looking for a light, uplifting fantasy read, or a plot dominated by action and danger, if you demand that your main characters be heroic, that magic be wondrous rather than technical, and that characters' social bonds be idealized examples of True Friendship, keep looking. The Magicians is a realistic novel that examines the pitfalls of escapism and why magic probably would be bad for you. It borrows from well-known fantasy novels in order to deconstruct them, but don't let the Harry Potter and Narnia comparisons fool you: this is a serious, adult book, and if you generally don't like literary sorts of novels, then you won't like this, regardless of its fantasy elements.
So, then, the plot. While trying to apply to Princeton, whiz kid and fantasy fanboy Quentin winds up being accepted to a college for magicians. But despite learning magic (which isn't easy) and discovering booze and sex, Quentin remains dissatisfied, still looking for the meaning in his life. As it turns out, being a magician isn't such a great thing after all. One character explicitly wonders whether people with the power to alter reality can ever really grow up, and for Quentin--who graduates only to discover that he has no responsibilities and nothing to strive for--the answer is no. Finally, he and his friends discover a way into Fillory, the mystical Narnia-analogue Quentin has been obsessed with since childhood, but as the reader will have guessed, the real Fillory proves to be anything but a magic solution to his problems.
There's a lot to like in this book. The plot, though slow-paced, is always interesting, and the characters are nothing if not true-to-life. Their interactions and group dynamics are so typical for a group of young people that I started to wonder what's wrong with all those other authors who don't write about people this way. The prose style is very good and thematics are strong, providing plenty of food for thought. Grossman's take on the magical academy and the traditional Fantasyland is interesting and refreshing. Yes, he borrows heavily from other books, but that's the point; and, crucially, he strips away the idealism, asking what would really happen if, for instance, a tiny segment of the population was born with the ability to use magic.
That's not to say that the book doesn't have its flaws. Grossman doesn't seem to realize that any fantasy reader mature enough for this book will have moved beyond Harry Potter and Narnia into mature, adult works, and therefore neither "magic won't solve your interpersonal problems" nor "real battles are gory and terrifying" is new or startling. At times figurative language gets in the way of clarity, rather than enhancing it. And Quentin's girlfriend is noticeably less realistic than the other characters, transforming from a cripplingly shy geek to a somewhat nerdy babe far too rapidly.
I would recommend this book to those who are interested in literate, realistic sorts of fantasy books. It won't be much like any of the works it alludes to, but is worth your time nonetheless.