Just to add some info ..
If you plan on watching on a low quality Standard Definition TV (like a 13" - 25") than it doesn't really matter you will be happy with both.. BUT,
If you plan on ever watching on High Quality TV's or HDTV or large monitor than the only choice is the ATI (so far, the new matrox should be a contender) Let me explain...
also you can find any of the following information (confirmed) over at
www.avsforum.com.
ATI uses special hardware to not just handle prosessing but to also handle the way the image is assembled from the digital format... Nvidia has included this only on the GF4MX cards but has not yet added support in there drivers... Just like my friend who thought that svcd's were just as good as DVD, you may think you are getting a good quality picture untill you look at them back to back.. then you will see there is a very large delta between two cards... Nvidia is the King of 3d... and that is where they focus and care... ATI is the king of DVD and they are the only people there right now... also the 8500 is at least as fast as the GF3ti500 and even beats the GF4ti4200 is nome tests(not many)... good luck...
John Crawford