I haven't played FPS for along time so I can only recommend these three:
If you're looking for a Team-Fortress-like FPS then I recommend Overwatch, it has so huge players base.
If you're looking for a more realistic FPS, I would say Battlefield 1 released recently, it has pretty good and fun gameplay, and it creates quite excellent warfare feeling on a battlefield.
Another recommendable choice would be Titanfall 2, it is so excellent in both multiplayer and campaign (the campaign is surprisingly good, trust me) which combines realistic warfare and a bit advanced technology (like the giant robot). What piques my interest is that it isn't that popular compared to other FPS, even though the game is good and should be suggested.