first of all wuts ur budget? if its around $1000 +-500, i could suggest some stuff.
mobo - DFI LANParty NF3
cpu - amd athlon 64 3500+
vid - nvidia 6800gt
case - thermaltake tsunami (i love this case)
hard drive - western digital, seagate 120gb
ram - corsair or ocz or kingston depending 1 gig
you can decide on the little things this is just to start u off.