Upgrade Suggestions?

Hi there, long time lurker, first time poster.

Although I am very satisfied with my current PC, I feel like it could perform even better. My question stems from my inability to decide which component would give me the biggest overall performance benefit. Specs below, thanks for any suggestions!

 

  • MSI Z77A-G45 Mobo
  • i5 3570K (OC to 4.3GHz)
  • 8GB HyperX Blu DDR3 1600
  • XFX Radeon HD 7870 GHz Edition



Probably the GPU, but a 7870 is still a pretty good performer.

I'm just not sure if the additional performance would be worth the cost right now. I might wait one more generation then. Like I said, I'm satisfied with it, just feeling the urge to put something new in it I guess.