Need a graphics card for Oblivion.

Once upon a time, I got the Intel Retail edge bundle of 2005 and built myself a computer.

Pentium D 820
D945Psn w/ integrated sound
2Gigs of DDR2
200Gb SATA HD
500W PSU
Win XP Pro.

I bought myself a low end PCIE card a while back, it played all the old games I had from my old computer. And then I bought Oblivion. My old card will play the game at all the lowest settings at about 30FPS. So, I need a new card before I put a hole in my computer or gouge my eyes out.

I know that if I put the best card on the market into my computer it will be a waste of money, becase I have a two year old processor.

What I want is a graphics card that will run Oblivion on my new shiny 22" monitor at full resolution (1680x1050) and full graphics settings, without the card being faster than my CPU can handle. For less than $200 dollars.

I doubt this is possible, but I'd like to know my options: The best I will be able to run Oblivion for under $200, the absolute best I will be able to run Oblivion on my machine and how much that would cost, and hopefully a happy medium.

Thanks in advance for your help!
`n0
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Added PSU, HD and Mobo
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Fixed resolution.
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I was browsing the fourms and saw that the GForce 7 Series is highly recommended, is this card a good deal?

Well...

All graphic card having 256Mb+ are good for Oblivion.I played it on 1900 radeon pro 128Mb,med details 800x600.nvidia is much better but i can give u the name of a card that is much more better:MSI NX8800GTS-T2D320E-HD-OC(320 Mb).It eats the test for oblivion and if backed up by your DDR it will be ultrapowered.The card is not expenisive,nearly around 100-120$.(200-220 e).

Give THIS one a gander. It should do everything you want it to. You can check the VGA charts at Tomshardware.com to be sure though.

Something else you will want to consider is to check and make sure that your power supply is up to the task of powering this very hungry card. Take a look at the sticker on your psu, you will probably need to remove the side panel to find it. There should be a small chart on the sticker showing various amps and voltages. You are interested in the AMPS on the 12+ volt line(s). 26 amps or more should be sufficient.