Here is what I have come up with.
ASUS M2N32-SLI Deluxe Wireless Edition AM2 NVIDIA nForce 590 SLI MCP ATX AMD Motherboard $169.99
http://www.newegg.com/Product/Product.a ... 6813131011
AMD Athlon 64 X2 4600+ Windsor 2.4GHz 2 x 512KB L2 Cache Socket AM2 65W Processor $87.99
http://www.newegg.com/Product/Product.a ... 6819103773
CORSAIR XMS2 2GB (2 x 1GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory $88
http://www.newegg.com/Product/Product.a ... 6820145034
XFX PVT88PYDF4 GeForce 8800GT 512MB 256-bit GDDR3 PCI Express 2.0 HDCP Ready SLI Supported Video Card $269.99
http://www.newegg.com/Product/Product.a ... 6814150252
Seagate Barracuda 7200.10 ST3250410AS 250GB 7200 RPM 16MB Cache SATA 3.0Gb/s Hard Drive $69.99 (your pick)
http://www.newegg.com/Product/Product.a ... 6822148262
I have several 6xxW Power Supplys and may even be modular that will let you have for $100 or less. Will have to look to see what I have when your ready.
Microsoft Windows Vista 32-Bit Home Premium for System Builders Single Pack DVD $111.99 (your pick)
http://www.newegg.com/Product/Product.a ... 6832116202
COOLER MASTER RC-690-KKN1-GP Black SECC/ ABS ATX Mid Tower Computer Case $59.99 (your pick)
http://www.newegg.com/Product/Product.a ... 6811119137
LITE-ON Black 20X DVD+R 8X DVD+RW 8X DVD+R DL 20X DVD-R 6X DVD-RW 12X DVD-RAM 16X DVD-ROM 48X CD-R 32X CD-RW 48X CD-ROM IDE DVD Burner $24.99
http://www.newegg.com/Product/Product.a ... 6827106049
That comes to a total of $982.93 before shipping.
You can drop down to a slower CPU if you want to save a little but I picked a good midrange one. The video card is the new 8800GT which will play anything you want. You could go with a cheaper video card but for the money I would go with the 8800GT and if you wait a few weeks till they release the other versions of the 8800GT you might be able to get it even cheaper. The PSU's I have are all new and still under warranty and depending on which one I find to work the best for you I can make you a good deal on it.
You can tweak all of that to bring down the price or if you wait till after the first of year you could get some betters deals as all of the new stuff will be coming out then and the prices on this stuff will drop.