There are so many to choose from as far as a favorite. I go through phases with many authors and devour everything I can locate from them.
Through the years there was the Ed McBain phase, the Samuel Butler time, a brief visit with John Lescroart, an on and off trip to Ernest Hemingway and am now in the midst of a Joseph Roth vacation.
I'll possibly take a journey to science fiction soon, it's been too long a while since I've been there.
Favorite books would include Alexsandr Solzhenitsyn's One Day In the Life of Ivan Denisovich
, Carson McCullers's The Heart Is A Lonely Hunter