Upgrade

[Garfield360]

Hi, i have a AMD Athlon 64 3000+ with an ATI x400 and 1 gig ram and 40 gig hard disk and crt monitor and onboard sound. What i am wandering is what to upgrade to play the latest games such as half life 2 episode 1 , toca race driver 3 , battlefield 2 at a good frame rate and with niceish graphics?

I dont want to spend loads on a new computer and sound doesnt matter to me loads so the onboard sound is good enough for me.

Any suggestions will be notified:-k