Ok here...for $2400 (all prices Newegg.com):
Core 2 Duo e6850 3.0ghz 1333 FSB $266 after July 22 price drop
GIGABYTE GA-P35-DQ6 P35 Motherboard $229
4 GB Corsair PC1333 DDR3 memory $778
2x 150GB Western Digital Raptor Drives in RAID 0 $330
MSI 8800 Ultra 768mb graphics $579
X-Fi XtremeGamer Fatal1ty Pro $145
MSI TurboStream 600W PSU $80 (may get one with more wattage if possible)
2x Lite-On 20x DVD Burner w/ LightScribe $62
Coolermaster Centurion 5 Case $40
Stock Cooling: Free
That's $2509. You could knock off a hell of a lot if you went with a P35 DDR2 motherboard with fast DDR2 memory. DDR3 memory, as you can see, is very expensive. I personally wouldn't spend so much on memory, but for performance it is the best. I would, however, still suggest 4GB for a $2400 build though. All the other components though are stellar. That Core 2 Duo is the newest Core 2 and it will perform wonders in games, as will the 8800 Ultra (the best single card). I personally own the Coolermaster case and can vouch for its excellence. If you want to knock off some money (although the DDR3 memory would be very nice), I would suggest thinking about using some of it for: liquid cooling, TV Tuner (Vista View Saber is a nice PCI-e x1 card), blu-ray or HD DVD drive, more storage (e.g. a 750GB additional hard drive). Those dual raptors will do nicely for gaming though. I didn't know if you needed an OS or not, so I didn't include it. If you are strictly a gamer, and I mean strictly, then go with XP Pro. Otherwise, get Vista Home Premium. I run Vista Ultimate and it is far better than XP. But, for sheer performance (although with those components I don't see you suffering), XP is better. You can run Vista without a hitch with those componenets though. Anything else just let me know.