Alright, this does end up costing a little bit more, but sets up up better (the main issue is the motherboard cost) I can adjust it if you want the bottom line lower.
MB : Asus M5A99X EVO $144.99 3-Year http://www.newegg.com/Product/Product.a ... 6813131754
CPU: AMD Phenom II X4 955 BE $119.99 3-Year http://www.newegg.com/Product/Product.a ... 6819103808
RAM: Corsair XMS3 4GB DDR3 1600 $26.99 Lifetime http://www.newegg.com/Product/Product.a ... 6820145328
GPU: EVGA GeForce GTX 460 SC EE $199.99 Lifetime http://www.newegg.com/Product/Product.a ... 6814130568
PSU: Antec BP550 Plus Modular 80+C $54.99 3-Year http://www.newegg.com/Product/Product.a ... 6817371016
HDD: Western Digital Caviar Black 750GB 64MB 6.0Gb/s $54.99 5-Year http://www.newegg.com/Product/Product.a ... 6822136794
DVD: Asus Burner $18.99 1-Year (second year is $5.99) http://www.newegg.com/Product/Product.a ... 6827135204
That gets a total of $620.93, not including shipping or tax.
If you want to go lower ... it might come down to the $550 range. If you want to go a little higher it'd be in the $750 range (6 CPU and a GTX560 and a board that can do 16x dual SLI instead of 8x)
With the board, I'm only allocating one stick of RAM, it supports 4. That'd max you out at 16GB for now. The board actually supports 32GB total, but 8GB sticks of RAM are very expensive, it's definitely something to look at in a few years.
The CPU socket supports AM3+ ... that means the board supports the AMD processors coming out later this year. Which also means in a couple years upgrading would be easier.
The board also supports crossfire and sli. So if you wanted to get an additional GTX460 (or 560) it wouldn't be a big deal.
The power supply I chose will support the system upwards of a six core phenom II and a GTX560 with 16GB of RAM. If you did something like, get a second video card, you'd need something in the 800W range.
Anyway, let me know if this is cool, or up or down. This setup right here will play something like Crysis 2 at 30fps or so using the highest settings. (As reference) You'd be pretty set for games (this has more to do with the GPU than anything else)