Best graphics card for an older system

[Midnight_Runner]

I'm trying to choose a new(er) Graphics card for my computer. I have a PCIe 1.0 x16 slot and I know that PCIe 2.0 graphics cards are backwards compatible. However I don't know where I would be buying more graphics card than my computer could use.
I just want the best card for my system specs. No point in putting a Corvette engine inside an old Model T. I do however want the absolute best card that my system can handle/use.

BUDGET RANGE: 90$ - 200$

USAGE FROM MOST TO LEAST IMPORTANT: Gaming (Starcraft 2, Sins of a Solar Empire: Rebellion, Team Fortress 2, Portal, Possibly a more modern FPS if i) Streaming movies and playing HD Video @ 1080p resolution, Dual monitor capability preferred.

CURRENT GPU AND POWER SUPPLY:
Current GPU: Galaxy GeForce GT520
750 Watt Power Supply with 6 Pin Connector for GPU.

OTHER RELEVANT SYSTEM SPECS:
AMD Athlon 64 X2 5000+
Asus M2N61-AR (Acacia) Motherboard
2x2GB DDR2 Corsair RAM

PREFERRED WEBSITE(S) FOR PARTS: Newegg.com, Amazon.com, Tigerdirect.com, Microcenter.com and even (in a pinch) Ebay.com

COUNTRY OF ORIGIN: United States

PARTS PREFERENCES: Nvidia

OVERCLOCKING: (Maybe?)
SLI OR CROSSFIRE: I have no idea.

MONITOR RESOLUTION: 1024x1280, 900x1440, and up.

 

[clutchc]

From your monitor list, it looks like you are planning on upgrading to higher resolution. Almost any card can do streaming and blu-ray at 1080p. Gaming is a different situation. Your older processor is, of course, going to bottleneck any mid-range card. But I feel it's better to have a card the CPU bottlenecks than the other way around. Who knows? you may upgrade the rest of the system someday
GTX 560: http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&N=100007709%20600094002%20600158457&IsNodeId=1&name=GeForce%20GTX%20560%20%28Fermi%29

If you want to keep the card better balanced with the aging Athlon, I would suggest the GTX 550ti:
http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&N=100007709%20600094002%20600122953&IsNodeId=1&name=GeForce%20GTX%20550%20Ti%20%28Fermi%29
It should give you good frame rates up to 1400x900 with the old Athlon I.

 

[Midnight_Runner]

Best answer selected by midnight_runner.

 

[Midnight_Runner]

I've opted for the GTX 560 (Probably one of the Galaxy models) because I keep a number of computers besides my own running, so when it inevitably dies I'll move the card to another computer and it can breathe new life into that system. That card is quite well within my budget range and is pretty much perfect - thanks

 

[Mousemonkey]

This topic has been closed by Mousemonkey