It all depends, mainly on your budget and how ambitious you want to be.
Your CPU would be the first thing as it is just a dual core. The sticking point is the age of the socket and what your motherboard can actually run. While FM2 CPUs are still out and available it has hit EOL (end of line) meaning you can upgrade with your current mobo for now and push back the inevitable for a while.
If you are ambitious you can upgrade CPU and mobo. Intel just dropped prices due to AMD releasing the Ryzen chips but you would have to choose the CPU/mobo combo carefully to ensure that the mobo could use your RAM (which I assume is DDR3). An AM3+ CPU/mobo is an option but they have just hit EOL as well.
If you have the money you can go with Ryzen but only the top three R7 chips are currently out, the 1800X, the 1700X, and the 1700. The R5 and R3 chips should be out next quarter IIRC. Upgrading to Ryzen, either now or then, will require DR4 RAM as would the latest from Intel.
Your GPU, while not a top end cord, is still a decent performer for all but the top end games. It can run the top end but on low settings for the most part. It comes in just under the GTX 760 which was my previous card which is still a good card for gaming.