With a budget of 500$ what VGA card should I buy?

When it comes to computer hardware I’m a newbie, and recently I’m trying to buy a new VGA card, and since I fixed a budget of about 500USD for it I got confused on whether to buy:
NVIDIA’s 6800 Ultra or,
ATI’s X800 XT.

So, what do you people prefer…….
P.S.
I found a previous thread about VGA cards but it talks very shallow about these 2 cards.

Thank you,

I recently bought ATI RADEON 9600 PRO which costs only like 130$ and I'm very satisfied. Before I used NVIDIA, but because they abandoned MX users I'm now with ATI

maybe you should look for benchamrks and tech info to know which is better, but I think I'll buy ATI :P

If you're set on spending that much, I'd get the x800XT. It's not quite as fast at Doom 3, but faster on many other games. You might want to consider the nVidia 6800GT, which can OC to Ultra speeds while saving you some money.
Basically though, either one of those cards kick a$$ compared to anything else out there, and you'll be happy with either. What are the specs of the rest of your system?

Well Karsh, These are the rest of the components(i hope im listing them right):

CPU :AMD Athlon 64 3200+....
MainBoard: (MSI somthing.... )
HD: Western Digital 120GB 7200RPM Serial ATA
RAM:kingstone 1GB.

and with a total cost of about 900$...

tell me is it a or a price???

thanx.

If its $900US for just what you have listed, thats quite a bit.
From newegg:
AMD 64 3200+: ~$205
Mobo: ~$150 (most expensive one there)
HDD: $92
RAM: $300 for the best
Total: $747
If your total included other components (case, psu) of course, it becomes pretty reasonable.
Sounds like a pretty nice box