Gaming Rig

[JamesA95]

Hey guys, looking for a gaming rig spec, currently using a laptop with integrated graphics and whilst its not terrible its not exactly the best.
Basically looking for a not too expensive gaming pc. By that i mean no where near the £1000 mark. Ideally I'm looking to just buy a built computer.
Game wise, Battlefield, some mmo's

Edit: also looking for it to be easily up gradable

 

[JamesA95]

I'd like to spend around the £600 mark, that's just for the PC. The rest I can sort myself. I'd prefer to buy a ready built PC. Although a spec for both would be great. So I can compare