Player Unknown's Battlegrounds, holy shit what a game. Still in Steam Early Access so it has bugs and needs a lot of optimisation/polish, but the concept of it is incredible. Some of the most intense fighting ever. In fact, most of the time I've been actively avoiding fighting, so when it happens its scaray as shit. Get it now in early access so it's half price, cos it's already worth it.
If you don't know what it is, the basics are: You jump out of a plane onto a 8x8km island with ~ 100 other players. None of you have equipment other than clothes. Scan the local buildings for guns and supplies. Then after a few minutes, a circle closes in that you have to be in. The circle gets progressively smaller the longer the game goes. Kill or be killed. Last one alive wins. Think Hunger Games/Battle Royal, but done way better than any previous attempts. http://store.steampowered.com/app/578080/PLAYERUNKNOWNS_BATTLEGROUNDS/