The worst of 2016 for me was clearly "The Great Gatsby". My favorite ones were a tie, I've been fortunate with some amazing books this past year. I think I have to go with A Court of Mist and Fury, Crimson Bound, Six of Crows, Magnus Chase and the Sword of Summer and An Ember in the Ashes.
My picks for the worst were The Woman in Cabin 10 and A Headfull of Ghosts
My favorite ones were Slade House, Ready Player One, Full Dark, No Stars and The Ocean at the End of the Lane.