Zombies. Fucking zombies.
They were ridiculously overdone, tired and boring by late last gen and at this point I never want to play another zombie game again. They're not scary, they're not fun, they are nothing at this point but the embodiment of creative bankruptcy.
It's pretty obvious why zombies became what they became. It's not just it being an artistic trend or whatever, it's moreso due to the fact that they're an easy replacement for the average videogame baddy. If you want to make any "mature" realistic game filled with gore and killing people, but you don't want the actual killing people part to raise eyebrows, just make them zombies and voila, there's the generic basic enemy you can use for your entire game.