Bump that up to about $150 and you will future-proof your video for quite a bit longer. Think about it; an additional ~$50 investment will roughly double your overall video performance. There are several nVidia and ATI cards in that range that are a vast increment above the sub-$100 cards. The ATI 9200 series and nVidia FX5200 series just don't have the oomph for high-demand gaming. I have a slight preference for nVidia due to better Linux support and a more-robust driver model. Boards in the $150 price range include those based on the nVidia FX5600 and (newer) FX5700 series and the ATI 9600 series. 256 MB RAM is a good idea.

Most new cards are 4x/8x AGP compatible, but it doesn't hurt to check.

In your new MB, avoid the Celeron like the plague that it is. I prefer the AMD Athlon series.

Most cards in that price range have both VGA and DVI outputs, so you can use a dual-monitor desktop. It's pretty cool.

Thanks, that definitely helped. Speaking of the nVidia cards, I think I kind of like them too. I really liked my GeForce2 that I have. It was a PNY; are there any manufacturers, to look for or even avoid?

PNY is decent. Another safe bet is a card made by a major motherboard manufacturer like Abit, ASUS, MSI, Gigabyte, Albatron, etc.

For more-detailed specs, comparisons, and ideas there are a number of news and review sites that you may find useful. The leading nVidia fan site is nVNews. The leading ATI fan site is Rage3D. Then there are the trustworthy non-aligned sites like The Guru of 3D (a good source for drivers) and PCStats. Other sites include Tom's Hardware and AnandTech... and then there's the always-amusing [H]ardOCP.

If you need more info, feel free to ask.