I am currently using Windows XP Pro (ie DirectX 9.0c) for games. My display max resolution is 1280 x 1024.
All the current high end graphics cards really aim for insane high resolution gaming, right?
Also DirectX 10 offers more features, therefore a higher spec of GPU is necessary.
I wonder whether a Nvidia 8600GT is more than enough for DirectX 9 in 1280x1024. Nvidia 9800GT is just over the top, right?
Meanwhile, I will stay with DirectX 9 for quite some time as I have no intention to upgrade to Vista.
If you are planing to play on 1280x1024 with antialiasing on you're ganna need more than a 9800Gt
If you want to play the latest game on High or Ultra High res. I thing you should get the ATI 4850 that is a great one for your situation.
and about the CPU go for e8500
MB: P35 DS3R FBS:1333 (OC:1600) DDRII 1066 (OC:1200)
VGA: ATI Radeon HD 4870 512 MB
CPU: Core 2 Quad Q6600 oc@ 3.3 Cooled with ASUS Tritton79
RAM: 4x1GB A DATA 1066+ OCed to 1100
HDD: WD 500 GB 32MB 7200 RPM
PSU: 500W Amacrox
4850 is awesome for the money....really really cant speak highly enough of it. I picked my overclocked powercolor off eBay for £90 (£133). Thats about $20 more than a 9600GT, and another $20 for a mail in rebate from Newegg.
Not only will you run the games listed, you will run them well.
If you cant afford the extra $40 then stick with the 9600GT, it will give you some fun.
9800GT would be plenty for 1280x1024. The 4830 would be good at that resolution as well. The 4850 would give more life though, but probably not much more.
Your cpu is fine. I use an e6750 and I'm maxing out every game I have sans Crysis of course. I play at 1680x1050 or 1920x1080 with a 4870, but my CPU isn't keeping me from playing all the new games at high settings.