I mostly read series, and my favorite is Malazan Book of the Fallen by Steven Erikson. The Silo series by Hugh Howey a close second.
I’m not really someone who reads many standalone books, because I love getting lost in epic/long stories (for this same reason I barely ever watch movies and stick with series in stead), and I hate how by the time I’m really getting into a book, suddenly it’s over… But hmm, for a standalone book I’d have to go with The Book Thief by Zusak (which btw, never seen the movie, maybe I should sometimes).