Short answer: The one you like the most.
Long answer: Depends on your definition of "best" doesn't it? Do you mean the best rep, best gen, most accurate rep, best value for money, best timekeeper, deepest diving, most complications, toughest or what? IMO the "best" watch available right now is the Patek Sky Moon but you may not have 1.5 million to spend or you may not like dressy watches. What are you going to do with said watch? What role will it play, what is expected of it? Will it be worn in a board room or a war zone? So many variables.
Apart from the answer at top (which is the correct one after all) it's an impossible to answer question without more infomation.