With a number of up-coming games I'm worried about my pc not being good enough to run some of them. For example, I saw that one system requirement for CoD: MW2 was a 7800 graphics card or better - I only have a 7300.
I'm looking to upgrade my PSU and GPU for under £100 and to run these games at least.
Its got a pciex16 slot so any pcie graphics card could work. You just need to get a PSU that matches the graphics card you get. Usually the manufacturer site gives a recommended power supply and number of pcie power cables.