Long time, no entry, so here goes...
Video Card Market Gets More Interesting
Now the market has settled down somewhat, the picture is starting to emerge.
For the economy segment, NVIDIA appears to have the lead with the GFFX 5200 series. The GFFX 5200 can often be found for under $100 after rebate. The Ultra version is a bit faster, but costs about $170, making it not worthwhile. The GFFX 5200 has DX9 hardware support. The ATI competitor, the Radeon 9200, while about as fast, is only DX8. At least that it on paper.
In reality, GFFX 5200 is really TOO SLOW to truly exploit the DX9 features. When used in "budget" machines that is 2.5 GHz or slower, the card is self-limiting. The Ultra version is not that much better. The 9200 is basically AGP8X version of 9100, and it's actually a decent performer, if not too spectacular.
In the mid-grade segment, you have the GF FX 5600 / ultra, and the Radeon 9600 / Pro. Here, you're looking at slightly slower version of the top-end stuff, and this is where the TRUE value is, as these are often under $300, and has about 80% of the performance. Both are plenty fast, and both are overclock-able. It's hard to say which is faster. It depends on the benchmark...
As for high-end stuff, 9800/pro and 5900 / ultra are neck to neck depending on which benchmark you run. Lots of fun, eh?