Here's is one option:
CPU - $165 shipped!
AMD Phenom II X4 955 Black Edition Deneb 3.2GHz 4 x 512KB L2 Cache 6MB L3 Cache Socket AM3 125W Quad-Core Processor - Retail
http://www.newegg.com/Product/Product.aspx?Item=N82E16819103674
Mobo - $88 - $10 MIRc = $78!!
GIGABYTE GA-MA770T-UD3P AM3 AMD 770 ATX AMD Motherboard - Retail
http://www.newegg.com/Product/Product.aspx?Item=N82E16813128392
GPU - $117 shipped! Not the fastest GPU, but will do everything quite well.
XFX HD-477A-YDFC Radeon HD 4770 512MB 128-bit GDDR5 PCI Express 2.0 x16 HDCP Ready CrossFireX Support Video Card - Retail
http://www.newegg.com/Product/Product.aspx?Item=N82E16814150369
Case/PSU comob - $100 shipped!! You get a nice case and a 500w (34A on the combined rails) for a very good price! The PSU has 2 x 6 pin PCI-e power connectors for future GPU upgrades, if you want/need them. The 4770 only needs 1 x 6 PCI-e power connector, so that leaves 1 more for crossfire or if you upgrade to a bigger (more power hungry) GPU!!
Antec Sonata III 500 Black 0.8mm cold rolled steel ATX Mid Tower Computer Case 500W Power Supply - Retail
HD - $55 shipped!! One of the faster HD's out there in the 500gb size. You can spend more and get bigger, but this would be a good OS drive to have. Than just add a data drive (1 TB or larger if you like) if you want more.
SAMSUNG Spinpoint F3 HD502HJ 500GB 7200 RPM 16MB Cache SATA 3.0Gb/s 3.5" Internal Hard Drive -Bare Drive
http://www.newegg.com/Product/Product.aspx?Item=N82E16822152181
RAM - $94 shipped! One of the better RAM sets you can get that run at stock voltage (1.5V)!
G.SKILL Ripjaws Series 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Desktop Memory Model F3-12800CL9D-4GBRL - Retail
http://www.newegg.com/Product/Product.aspx?Item=N82E16820231277
DVD Burner - $39 shipped! You can get OEM versions, but this "Retail" version comes with the software to read/burn DVD's!!
LITE-ON Black 24X DVD+R 24X DVD-R SATA Black 24X DVD Writer - Retail
http://www.newegg.com/Product/Product.aspx?Item=N82E16827106334
OS - $105 shipped! Get the 64 bit version so you can upgrade your RAM past 4 gb's and get full use of the extra RAM!! Now if your a student with an ".edu" email address you can get Windows 7 for $30, so that would be a $75 savings!!
Microsoft Windows 7 Home Premium 64-bit 1-Pack for System Builders - OEM
http://www.newegg.com/Product/Product.aspx?Item=N82E16832116754
Microsft Upgrade for $30, link below:
http://windows7.digitalriver.com/store/mswpus/en_US/DisplayHomePage?resid=Sz6@7QoBAiMAADxZ8m8AAAAT&rests=1262403308432
Total ~$758 - $10 MIRc = $748!!
Now you can get an Athlon II x4 620 or PhII x2 550 BE for ~$65 less than the PhII x4 955 BE. This $ could be spent on a better GPU than the one listed above. I'd recommend this GPU if you decide to go with the 620 or 550 BE over the 955:
GPU - $155 shipped!! Has Dx11 and 2 x DVI, 1 Display port, and 1 HDMI output ports!!
SAPPHIRE 100283-2L Radeon HD 5770 1GB 128-bit GDDR5 PCI Express 2.0 x16 HDCP Ready CrossFireX Support Video Card - Retail
http://www.newegg.com/Product/Product.aspx?Item=N82E16814102864
The 620 or 550 BE matched with the 5770 GPU is a better gaming setup for ~$25 less. If you wanted a bit more CPU power than the 955 is the way to go. The Athlon II x4 620 or PhII x2 550 BE is less of a CPU, but mated with the 5770 GPU, you should have better FPS than the 955 w/the 4770. You can decide which way you want to go.