I am considering in upgrading the onboard graphics on my PC
I was thinking of the Geforce 6800 XT
My PC has specs: P4 HT 2.8Ghz, 1Gb RAM, PCI-E x16 and embarrassingly a 305 Watt PSU.
Which graphics card would be advisable for me to upgrade to?
Do they even sell the 6800XT anymore?
I would recommend for you something like a radeon HD2600XT for about $100 or a GeForce 9600GSO for a little bit more. My guess is your processor will bottleneck either card though.