You can get a, say, HD 6850 that would be a big upgrade. Or a HD 6870. The CPU is good for now, wait for the new AM3+ socket and the new Bulldozer CPUs (a few months away at most) and then decide between Intel and AMD. If you go AMD you will be able to use your current CPU and maybe unlock it. Also a Samasung Spinpont F3 500GB or 1TB if you need more disk space.