haha you can buy a proper gaming PC....but they are like 1-2 grand!!!!

You could also build your own like me its much better because you get what you want.
Umm you want to look for a computer with rougly these
3gb+ of RAM
500GB+ HDD you can always do what i do and buy extrernal drives for all my downloads, pics ect and keep the built in one for your programes, games ect..
The processor(CPU) you would want to be looking at one thats 2GHz+ but if you can get 3GHz

The graphics card should be half decent with the computer you buy if not just buy a new one to replace it.
A good tip is to look at the back of you PC games it tells you the recomended stuff you need so you just use that as a little guide
Hope this helps a little.