Whats the BEST graphics card you can get for QuickSilver?

ATI Radeon® 9800 Pro MAC Edition RoHS 256MB AGP
<http://shop.ati.com/product.asp?sku=3170663>
but it only has one DVI port (single-link)

Is it worth it in your eyes?

Yes.

What do you use it for?

Much faster 2D scrolling in Graphics Converter. Core Image allows video adjustment in QuickTime Player. Google Earth is now fun to use.

What's the CD ROM for? Drivers?

Tiger has the drivers. Get the latest ATI Displays from the ATI web-site. It gives you rotation and extra control of the video output.

Do you have any idea if it'll work with 10.5 when it
comes out?

It has Core Image which will be used a lot more by 10.5

Any quirks you think I should know of?

The fan makes a bit of noise, but mine got VERY quiet after about a year. I replaced it with the Vantec Iceberq 6 cooler. It blows the hot air directly out of the case, so the whole computer is cooler.

I do a lot of
video editing, do you know the the s-Video port can
output a second display rather than a mirror of the
desktop?

Yes, but you can't use all three ports at once.

Some very good recommendations here, but nowhere near the best.
That is the question you asked right?

GEFORCE 7800 GS or other variations on it is the absolute best there will probably ever be for Quicksilver G4s. Significantly faster than all 9800s.
Only caveat is they are quite a bit louder fan-wise.

GEFORCE 7800 GS or other variations on it is the
absolute best there will probably ever be for
Quicksilver G4s.

Which of these cards can be run in the G4 QuickSilver? Is there a dedicated Mac version or do I need to get a special make and model which needs to be flashed then?