The best deal I'm finding is via an affiliate site for dell:
i7-2600 8mb cache 3.4ghz processor
12 GB ram DDR3 @ 1333mhz (4 dimms)
1 TB HD SATA 3gb/s
ATI Radeon 5450 1GB DDR3 vid card
Windows 7 home premium
MS Office Home and Student 2010 (vs a gimped version)
2 year service/support
Total is $1010 with a coupon and discount, plus tax.
You could bump the video card to DDR5 for an extra $70, and/or the hard drive to SATA2 for an extra $50.
They also have an alternative configuration where you could just go with the same stuff but with 8gigs of ram instead of 12. That will knock off about $160 ($850 total).
My strategy in the past has been to get a dell or something along those lines with the greatest discount on the core components, then buy the graphics card separately. Most brand name computer companies are never up to date on the latest video cards, and if they are, they charge you dearly for not buying it yourself and popping it in. On some occasions you would need to bump up the power supply, depending on how big you go.
If you check out the passmark comparisons you'll find you can get a graphics card that score upwards of 5-10 times higher than what they include (for example, you could pick up a Radeon HD 6870 w/ a free PC game for $180, and that is nearly a top 10 performer). EG: http://www.newegg.com/Product/Product.aspx?Item=N82E16814161349&cm_re=radeon_6870-_-14-161-349-_-Product
You could also take a look at HP for comparison, they offer similar deals. These two companies are pretty much neck and neck, they just offer slightly different things to tweak their pricing
The site I like to use for getting the latest coupon and discount info is edealinfo.com. If you roll through them you get the free upgrade to MS office and a $100 coupon off the dells. Often times if you aren't directed to the site by an affiliate, they won't show you all of the promotions they are offering, because they don't want to discount if they don't have to.
They've also got comparable offers on the HP.
I would personally recommend going with the 8GB system @ $850 then adding a better graphics card than what they offer. Installation of those is a snap. The only potential thing you'd need to be wary about is the power supply, but even those are extremely cheap.
Let me know if this is what you had in mind. If you've got more questions, I'd be happy to help. If you want some more references to opinion sharing fatwallet.com or slickdeals.net are also excellent references when watching for deals on components (among other things).