What's the best g5 video card w/ 2 DVI ports?

[M A V I C]

The "dog" forum lists out details on how to "flash" PC video cards to work on Macs.

Depending on what you're doing, either a 7800 GS or x850 would be the most powerful card you can get in there. http://www.barefeats.com/mutant3a.html

A 6800 would be a close runner up.