I agree with iam2the crowe, you should update your CPU, motherboard and RAM in order to not experience a bottleneck. Your best best would probably be an i3 2100 (some would go for a Phenom II but a recent Tom's article showed that the i3 was better in most circumstances even though it didn't have 4 cores) with 4GB (maybe 8GB since RAM is so cheap). After that, focus on a new graphics card. We need to know your budget. I know you said $200 for a graphics card (which is a good price point) but would you be willing to spend a bit more for new guts? Anyway a 6850 or better will definitely bottleneck your system (a 560Ti would be equivalent to a 6950). If you want to keep your current motherboard, CPU and RAM then I would suggest a 6770.