Hey guy's this is my first post on Tom's but I've heard many good things about yalls community. I'm about to build myself a new system for gaming/programming/media use. The last time I built a PC was about 5 years ago so I'm not quite up to date on the nuances.
APPROXIMATE PURCHASE DATE: 1 week
SYSTEM USAGE FROM MOST TO LEAST IMPORTANT: gaming, movies, programming, interweb fapping
PARTS NOT REQUIRED: keyboard, monitor, mouse
PREFERRED WEBSITE(S) FOR PARTS: newegg, tigerdirect
Based on your card, you can run Crysis and MW2 at full settings, but only if your display has a resolution of 1440 x 900 or lower.
Are you planning to use a 32-bit or 64-bit OS? If the former, then you don't need more than 3GB of RAM. Just get a 3 x 1GB kit from CORSAIR or OCZ.
To further trim your budget, reconsider getting a dedicated sound card. You won't be doing professional-quality audio work, will you? The integrated audio hardware of your motherboard already does a good job.
Lastly, based on your specs, you can make do with a 500-500W power supply. Again, only because it seems you won't be into serious overclocking.