For price-performance ratio, the absolute best option is to build your own PC. That way you choose the parts you want, and cut out the middle man's fees for building it for you.
However, for those who don't know how to build PCs (or can't find a close friend to help out), then CyberPowerPC, Doghouse, and a couple other boutique manufacturers will give you the best PC. Only issue is that they will charge you for it as well. Cyberpower is a fairly affordable brand to go with, and I haven't heard a lot of negative reviews or critiques about the quality. The deal that Crash shared looks good; the only bad parts (in my eyes) is that it's Windows 8 and the Video card. Win 8 as the OS is a toss-up; some people like it, others hate it. To me, I already have Win 7, and I'm not building a new rig anytime soon for another year. Plus, I'm not a huge fan of the UI for Win8 so I'll pass. For a new user, though, it may not be such an issue. The video card is arguably the biggest issue a builder can have because it's not the best price/performance card you can get. It's a good card, but you can do better. Good news is that the price they're charging, you do have the extra spending power to get such a card. I'll leave that up to others to recommend for now.