Information on silent video cards are coming soon. For now, learn how to cool your card yourself!
Cool Your Own Card
If you already have a decent card, and are looking to swap the loud dual slot cooler for something a little more refined, check these out:
Zalman VF700-Cu
The specs: 1350-2650 RPM. 18.5-28.5 dBA. So yeah, keep it in silent mode. In my experience with the full copper version on a GeForce 6800GT, silent mode cools better than the stock cooler. And it does so at a barely audible level. In my opinion, it should handle anything you can throw at it - even the newest chip out there - 7800 GTX. This cooler only weighs 270g too, so you don't even need to buy the aluminum version (unless of course you want to save $5 or so).
Zalman ZM80D-HP
If you have a cooler video card, such as a Radeon X600, GeForce 6600 and below, and want to go absolutely fanless, the ZM80D-HP is the way to go. The engineering of this unit is immaculate, and it goes together amazingly well. I use one of these on a GeForce 6600 in my HTPC, and it has held up to the test of time in a cramped, hot case for a while now. If it runs a bit hot for your liking, go with the cooler above, instead of adding the clunky optional fan.
We're almost there! Now that our video card is taken care of, let's see what we can do with that huge loud power supply you probably have ;)