Which Prebuilt desktops for decent all-around use? Already have a Geforce 8600 GTS video card?

I need a new cheap prebuilt desktop for decent gaming and basic use. I play FPS games, sports games, RPG games on my PC as well as basic web surfing and movie watching. I plan to use my Geforce 8600 GTS from my old PC unless someone reccomends me a desktop that comes with a better video card. I am willing to spend up to $500.|||you can just build a really good one for at least less then $550. and 8600gts isn't good enough for modern games. its good for game from 2007 and less. and u can see walk through from you tube and other site. or u can just buy a new one for about $400 and get like a good graphic card and a 500W psu. let me give u an advice NEVER buy a used desktop. trust me, i have been through it.