Generally the story is ATI cards have a little more performance then a comparable Nvidia, but the Nvidia software is a bit more stable.
Before we get into flamewar territory though, I’ll say this. I’ve found nightmare stories and success stories for every brand on the planet. I recently put a new box together from the ground up and bought a 9200 (it was $99 IIRC) as an inexpensive card to hold the fort until I upgraded. My computer would crash after 10 minutes, so I reinstalled the OS, but it would still crash. I tried it on 98, 2000, and XP, and it would crash crash crash. I tried to download new drivers, guess what happened? I figured the card must be defective, so I returned it, and decided I might as well go level higher, because I had now had a credit from the old card and some cash in my pocket. I got an ATI 9600, same 'ol story, DR. Crash. I did some research and found that loads of people hated ATI and their software. I also found out that their mothers never loved them, but that’s a whole diff story.
What’s the point you’re asking?
I swore off ATI forever, I told everyone I knew never, ever, buy anything from this company. I ended up buying an Nvidia and the same thing happened with that card. I finally discovered that I had a bad DIMM of ram that was causing me my problems.
I take other people’s bitching stories with a grain of salt now, so you should too.
In terms of a good card, the 9700 and 9800 are the top of the line. They are popular and supported well, and aside of the usual good/bad stories, people are very happy with them.
There are several different companies (Hercules, PNY, etc) that offer their version, but I personally would go with the ATI all in wonder 9700. If you want some multimedia capability go with the all in wonder, if you want straight performance go with the plain 9800.
This post didn’t make much sense, probably because I’m not much of a morning person. 