Need Help with budget gaming PC

APPROXIMATE PURCHASE DATE: Within the next 2 weeks - 2 months

BUDGET RANGE: US $500-750

SYSTEM USAGE FROM MOST TO LEAST IMPORTANT: Gaming is primary usage

PARTS NOT REQUIRED: Monitor (have 19" flat panel 1280x1024), keyboard (USB), mouse (USB), OS (have XP and Vista), audio speakers

PREFERRED WEBSITE(S) FOR PARTS:Trusted sites (e.g. newegg and tiger direct)

PARTS PREFERENCES: Prefer Intel CPU because of past familiarity, but would switch to AMD if it was better

OVERCLOCKING: No

SLI OR CROSSFIRE: Maybe

MONITOR RESOLUTION: 1280x1024

ADDITIONAL COMMENTS: Bling and appearance is of no concern. Would like to have it be relativly coll/quiet as my previous desktop with a P4 was neither. Thanks for the help everyone! If you feel the budget is simply too low for good value please let me know.

I am myself building an intel setup and i will get all parts by saturday so i need some advice on a few parts :

http://www.tomshardware.com/forum/267643-31-extreme

Well I currently play Mass Effect, Bioshock, Sims 3 (wife), and Neverwinter Night 2 on my old laptop (GeForce Go 7600)

I play those games with significantly reduced settings obviously, so i would like to bump those settings up, as well as be able to play the follow anticipated games:

Mass effect 2
Dragon Age
Bioshock 2
Fallout 3

Thanks for the help! If need be I could probably raise the budget to 850. Though I was hoping I wouldn t need to since I owned the monitor, keyboard, mouse, speakers and OS.

Ok, here's a quick build. There are some nits people could pick, but nothing major.

Like I said, my wife is using this case/PSU and it is nice and quiet.
Antec Sonata III 500 Black 0.8mm cold rolled steel ATX Mid Tower Computer Case 500W Power Supply - Retail
Model #:Sonata III 500
Item #:N82E16811129024

$149.99 -$65.00 Instant $84.99

Sony Optiarc 24X DVD/CD Rewritable Drive Black SATA Model AD-7240S-0B - OEM
Model #:AD-7240S-0B
Item #:N82E16827118030

$30.99 $30.99

I found that the 4870 fits in your budget fairly easily, so I included it. The only downside is the cooler doesn't exhaust ALL of its heat. You may want to add an intake fan to the front of the case to help push warm air out the back of the GPU.
SAPPHIRE 100259L Radeon HD 4870 512MB 256-bit GDDR5 PCI Express 2.0 x16 HDCP Ready CrossFire Supported Video Card - Retail
Model #:100259L
Item #:N82E16814102810

$139.99 $139.99

I own this mobo, in a box that has run 24/7 for months (except when I'm messing with it).
ASRock AOD790GX/128M AM2+/AM2 AMD 790GX ATX AMD Motherboard - Retail
Model #:AOD790GX/128M
Item #:N82E16813157141

$119.99 $119.99

You could fit a PII X4 here if you wanted, but why spend all your money on this rig?
AMD Phenom II X3 720 2.8GHz Socket AM3 95W Triple-Core Black Processor Model HDZ720WFGIBOX - Retail
Model #:HDZ720WFGIBOX
Item #:N82E16819103649

$139.00 $139.00

G.SKILL 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 1066 (PC2 8500) Dual Channel Kit Desktop Memory Model F2-8500CL5D-4GBPK - Retail
Model #:F2-8500CL5D-4GBPK
Item #:N82E16820231166

$54.99 -$5.00 Instant $49.99

Yeah, you could get a bigger one, in the same line, or a smaller. Or get two, one for OS, one for data.
Western Digital Caviar Black WD5001AALS 500GB 7200 RPM SATA 3.0Gb/s 3.5" Internal Hard Drive - OEM
Model #:WD5001AALS
Item #:N82E16822136320

$69.99 $69.99
Subtotal: $634.94

There's enough room in the budget for an additional 120mm case fan, or a CPU cooler if you decide to overclock. Like I said, it can be nitpicked, but I think shows that a reasonable build within your budget is entirely possible.

For about $5 more, you can swap out the CPU, mobo, and RAM for an Intel e8400, a Gigabyte P43, and 4GB of Mushkin DDR2-800. That's probably actually the better deal. You don't want a lesser Intel CPU, because they don't support the virtual XP mode in Windows7.