Hi, I'm also looking to buy a new gaming rig. You didn't mention if you wanted a desktop or a laptop. I'm looking for a laptop because I need it for work, so I kinda require mobility. So far I'm eyeing Horize, they have some neat machines and they give you suggestions too. There's also Alienware, smooth looking laptops but they seem a bit overpriced. I'd say you need a minimum i7 processor, 4GB RAM and a HDD 7200 rpm.
good luck!