If a choice is to be made out of these two I would suggest a ps4. I would tell you to upgrade your pc but I'mma take the benefit of doubt that you have your reasons and already decided not to do that. Playstation has shown diversity of exclusives and while xbox has been more shooter oriented in the past. I even bought a ps3 last year to play last of us and it has been the best game I have ever played on any platform. If graphics is your thing, then ps4 will have better graphics on games where developers would want to use each system to their potential. Both require you to have paid memberships to play online, however, ps is offering better games each month.
In the end, its up to you. Its what games you want to play and which system they are available on.