Just picked up a PNY Ti 4200 64meg card this weekend for about 120 bucks at a computer show. I know it's not a Direct X 9 card like the ATI but I needed something to replace my first generation GeForce DDR until Feb and the GeForce FX. This card breathed new life into my P3 733 system, I can run UT 2003 with everything set on high and have 15 bots running around with me without a stutter. With my old card my system would have puked it's guts. Same deal with Battlefield: 1942.
Depending on your upgrade cycle if you get enough YES votes for the ATI card I would probably lean toward that since you'd get a longer life span out of it since it's a DirectX 9 card. I'm just real comfortable with Nvidia and their drivers that's why I went with the TI 4200, I also plan on upgrading again in two months.