What sort of budget?
for about £700-£800
AMD opteron 144 (sct939) [stock 1.8Ghz core clockable to **** 2.5-2.8GHz on air!! (almost FX57 speeds)]
Zalman Fatal1ty fan, or Something equally as powerfull
DFI Lanparty Mobo
2GB Mushkin Redline [no bottlenecks with this stuff]
Nvidia 7800GT
74GB WD Raptor 10,000rmp SATA HDD
[Storage drive for films etc.. if you want 250GB is about £70]
Creative Labs Audigy 2 5.1 Soundcard [minimum]
DVD RW {pioneer or plextor}
Jammin has a simular setup but with 2GB Mushkin Extreme [not as good as redline]Extras [if needed/wanted]
highspeed LCD Monitor
Gaming Mouse
Keyboard [i like the MS Multimedia Keyboards but a lot of gamers like diffrent keyboards!]
5.1 Speakers, 5.1 Headphones or Noise Canceling Microphone [setup on Press to Talk with vent/teamspeak]
and if your a rich bugger you could add WaterCooling
Another 7800GT [run in SLI]
Aega Phyisx Card [
overclockers]
and change the Opteron 144 for a 148 or even a FX57/60