So I had recently sent back 2 7900'GS cards because they were causing massive artifacting all across the screen. My third one came in the mail today and has massive yellow and red artifacting (YAY A NEW COLOR). Now when I turn the resolution down there is very little artifacting, but the entire screen is mostly red and I can barely read what I'm typing.

This still seems like a video card problem....right? I just think this is ridiculous that I have to RMA this many times

3 bad cards seem odd. Perhaps you are doing something wrong...too much static around your rig?

Some things to check before giving up and returning the card;

Can you test the video card on another machine? or another monitor?

Do you have an old graphics card to test in the machine that the rma'd card is giving you problems with?

Have you tried wigling the monitor cable to see if anything changes?

Did you uninstall your old graphics drivers before installing the new ones?

Did you install the monitor drivers? "sometimes windows monitor resolution/refresh is incompatible with the monitor, until the drivers are installed"

Does your card have any additional power plugs that need to be plugged in?

If your card has additional power plugs that need to be plugged in; Does your power supply have them? Does it have enough amperage/wattage to handle the total system load?