Based on your criteria I went comparison shopping at Newegg.com (a 
reputable dealer but not the only one) and came up with the following:
Chaintech GSV86GT 512MB GeForce 8600GT 128bit GDDR2 PCI Express x16
Leadtek PX8600GT TDH 512MB GeForce 8600GT 128bit GDDR2 PCI Express x16
MSI NX8600GT-TD512EZ 512MB GeForce 8600GT 128bit GDDR2 PCI Express x16

Tom

Melani Gump wrote:
>   Hi,
>
>
>
> I have a Dell Dimension 5100.  I was wanting to know what a really good (and
> cheap) graphics card would be that is compatible to my computer.  I would
> like at least 512MB in ram and at least 6800 GT.  
>
>
>
> Can you help?
>
>
>
> Thank you, 
>
>
>
> Melani
>
>           
>
>
>   

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