Please suggest GPU according to my needs...

Hello,
I have recently assembled a new PC for myself. Its Configuration is
Intel e8400 @ 3.0GHZ,
2x2GB 800MHz Kingston RAM,
Seagate 500 GB HDD(7200RPM-SATA II),
400W PSU,
17" LCD Monitor,
Intel Original DG45ID motherboard.
Windows 7 ultimate x64

It wasnt intended for gaming nd all, for my office work only,
But i guess if i slip a decent GPU in it i would be able to run most of the games..

So please suggest me a good GPU which could run most of the games (at max or high details)and i dont have a big resolution..either

As far as i have seen over the internet, gt260 or hd4870 or 9800 gt should do fine for me but need suggestion,,
Also some people said go for nvidia cards as it has better drivers and physX nd stuff like that..

Some people said that for me hd4770 should do everything..and please tell me if i can put this GPU on my motherboard..as i guess it has a pci exprss slot only one in it....and do i need another PSU for it?

Please Help.
thankyou

Hey brother,

It is better to ask the Intel for the compatibility of the GPU for their product so click on the link to take a help.

Intel

whats your budget anyway ??