Fiction:
Mistborn from Brandon Sanderson.
We Are Legion (We are Bob) is great sci-fi, and very accessible.
Ready Player One is The basis of Spielberg's next movie and a great read.
A Monster Calls is a well written, short novel. (Devastating though).
Most anything by Neil Gaiman.
On Stranger Tides or The Anubis Gates by Tim Powers. (Frankly, Tim Powers is the best little known author in the SFF genre).
The Passage trilogy by Justin Cronin. Think zombies and vampire combined, but very well written.
A Song of Ice and Fire. It's very mature, and HBO has apparently made the series much more violent and sexy, but the books are truly excellent.
Cryptonomicon by Neal Stephenson.
Wolf Hall and Bringing up the Bodies by Hilary Mantel (basis of the Wolf Hall Masterpiece miniseries).
Jonathan Strange and Mr. Norrell is maybe the best novel I've read in the last decade (the BBC series based on it was ok, but pales in comparison to the book).

Nonfiction:
The Rise and Fall of the Third Reich.
1776.
Team of Rivals.
The Lost City of Z.
The Thief at the End of the World.