Well, like I tell everyone looking to upgrade:
Work out your budget first!
How much do you want to spend?
Then: What do you plan to do with the rig? You say gaming?
Only gaming? Or 3d apps, multi-media heavy apps?
Once you work that out, the rest will fall into place.
EDIT: No time like now to shamelessly plug my sticky at the top of this section.
If you are upgrading gfx, don't forget your PSU!
