If you like Forza, Gears of War, Titanfall or Halo more, than definitely you should get an xBox. If you like Infamous, Killzone, Drive Club, Bloodborne, Horizon Zero Dawn, Uncharted or Last of Us more, than you should get a PS4.
Although there is no big difference technically between the 2 consoles. Most of the games are now released for both consoles.
Maybe best advice would be get whatever your friends have so that you can play together and don't forget to consider the exclusive titles you care about!