If u have money, get nVidia 6800,
else ATi 9800 PRO (128MB Version)
I had used widest variety of cards, and I had this 5200FX once as well, I made a PC for some one with 100% same specifications. except I had 3000+ AMD and his was 2800+ AMD, and I put ATi 9800PRO 128MB in his.
but his PC turned to be faster than mine, not even in graphics, but Internet as wll. I said to myself, How come this be possible, everythign same, even his is slower than mine (200Mhz) and even I built both machines. then one Day I came to know the mystery behind,and that was the ATi card.
If you have extra money: Buy any of these:
nVidia 6800 Ultra/GT (not earlier series)
ATi 9800 XT 256MB (not X800)
else if not much budget, get:
ATi 9800 PRO 128MB (not 256MB)
be sure when buying ATi, it must be ATi Built (not third party)
Intel Core2Quad 2.66Ghz 12MB L2-Cache
4096MB DDR Kingston Hyper-X
XFX 9600GT AlphaDog
Seagate 2 X 320GB SATA2
LG L246WH Flatron 24"