nVidia 6800 is really powerful.
but earlier 9800 series was as well, very much, as in Intel, Prescott though is newest, still its said that Northwood was better in performance,
same story is with ATi, its said that (XT series specially) was best so far.
Intel Core2Quad 2.66Ghz 12MB L2-Cache
4096MB DDR Kingston Hyper-X
XFX 9600GT AlphaDog
Seagate 2 X 320GB SATA2
LG L246WH Flatron 24"