just note: here you can't ask for cracks or downloading programs other than freeware. that is your business.
anyway, do you play the highly graphical intense games like Doom 3, HL2, Farcry and such?
if you do, and money is not really much of an issue I would suggest these parts:
AMD Athlon 64 FX-55
currently the most powerful stock processor available, except for the Opteron 850 which is really friggin expensive, all socket 940 motherboards don't have AGP or PCI-E 16x slots for a good graphics card, and require ECC RAM (which is slow + expensive)
Abit AV8 3rd eye motherboard. this motherboard is very good because it supports higher HTT and RAM speeds
Nvidia 6800 Ultra. this is arguably the best graphics card out there, although has strong competition from the X850's
2x512MB PC4000 G.Skill (if you can find it) Kingmax or OCZ RAM
case: anything you like, but watch out for cheap ones, a lot of the time they come with cheap PSU's which can damage your system
monitor: you can find second hand 21" CRT monitors for really cheap now, but usually they are friggin heavy, so you won't want to take them to LAN's. if you go to LAN's often, you might want an LCD, although for gaming you'd want one with a good refresh rate (which are usually more expensive)
you could also get a 21" CRT, then an LCD to take to LANs
CD Drive: LG 16x dual layer DVD±R/RW
sound card: the onboard sound in the Abit AV8 is pretty good, but if you want a separate sound card, an Audigy 2 vaue is good
CntdwnToExtn: Nforce4 boards have PCI-E and normal PCI, they will never have AGP. if you get one, you can't get an AGP video card
not that there's anything wrong with PCI-E video cards