One of my favorite pastimes is wading through hordes of slavering brain-eaters with a nice length of sharp steel. There are more than a few games that offer this experience but in my opinion one of the best is still Left 4 Dead 2. Simple but engaging game play and the ability to play as both the Survivors and the Infected means the game is still playable 9 years after it's release. The addition of UHD resolution support means zombie brains have never looked more realistic. If (somehow) you don't own a copy of this game I highly recommend you check it out, preferably with 3 friends.
I try not to flame the console vs. pc war as I have spent many hours gaming on both. In general I prefer to game on pc, and this video was made playing a copy of the game I purchased on Steam. I love Steam for a bunch of reasons, but I won't go in to those now. For those that are curious here are my pc's specs.
AMD-FX8320 @ 4.1 ghz
16 GB DDR 1866 RAM
256GB SSD
1TB HDD @7200 rpm
ASUS ROG GT 1070ti A8G
LG 34UC79G-B Display