Seems I may have an extra $100 or so to play around with. I'm thinking of either upgrading to a quad core, upgrading to the 5750, or adding in a new case. My old case has a broken flap.
Leaning towards the quad core, since most of what I'll be doing on the PC is multitasking non-gaming applications or playing games that are pretty CPU intensive (large scale RTS like Supreme Commander).
Or should I maybe upgrade to 8gb of ram? I'm not sure which will benefit me the most.