This is a very opinionated thing, there's no "Best FPS" there's "Most Favorite" for each person. Personally I prefer BF1, was disappointed by infinity warfare's premise, but that game is decent, and as you said at least the single player looks interesting. But since the single player will be done in about 4 hours, and I'd like to play the game for several years at least, I'd stick with BF1 and other innovating online multiplayer games.
On the same note, as inspiration for you budding game devs. Check out No Heroes:
its made by a single person, and he's been working on it for 4+ years, he has remade it several times, and it has some interesting mechanics, like interchanging parts from one weapon to another, non-centered aiming, full destructible env, parkour, its almost comparable to the two games mentioned here