My core specs are:
AMD Phenom X4 9950 OC’ed @ 3.0ghz
Visiontek HD 4850 512MB w/ Aftermarket Cooler
Asus M3A79-T Deluxe Motherboard
2x 1GB G.Skill DDR2 1066 RAM

What would yield better results? Adding more RAM or adding another graphic card (4850) to do crossfire? I’m starting on a completely clean install of Windows XP Professional 32-Bit, and I’d like to stay out of the 64-bit OS’s if I can; so essentially I’d like to stay at 4GB of RAM. And with a clean installation, I’m not too worried with Crossfire conflicts with drivers or with games; I have a lot of time on my hands.

So what’d be worth it more? Another HD4850 or 2GB more of RAM?
I game at 1920 x 1200 or higher.