Hello. Now I know the opinion here on the forums is that it is better to build your own PC instead of buying a completed one from a vendor. I understand this, and agree as well. However, as of right now I am unable to. I won't go into specifics, but I can't. So, now the only option for me is to pick out a prebuilt system to buy.
I am using this to play games such as Starcraft 2, school work, and any other misc. task.
So far, here is the best prebuilt system I have found so far:
I've always been a fan of CyberPower (http://www.cyberpowerpc.com/) for those who don't want to build their own system. It allows you to customize your PC to fit your budget.
iBUYPOWER has a similar offering (http://www.ibuypower.com/) where you can customize your PC to your hearts content.
Just do some research on parts first. This site has some great monthly graphics card reviews, and some CPU reviews