6600GT is the best $200 card you can find, at least until ATI's X800 non-pro is actually available at MSRP, which won't be for a while.
yeah, PNY is absolute garbage. I've had to RMA 2 different Ti4200s, and my friend had one die as well.
As for XFX, i have one, and have no problems (it's the PCIe version, though). Overclocking is kind of mediocre, I get artifacts if i go for more than a 9% overclock, but i doubt that's an issue for you. The software bundle is lacking, but the card is really cheap, so i can deal with not getting a great game bundle. Oh, yeah, and the memory clock is 1GHz, versus the 900MHz that most AGP 6600GTs use, so that helps a bit at high resolutions. I mainly just like it for the dual DVI, cause i am planning to get another LCD with a lower response time (right now, I have to use my old CRT for games). BFG has the same dual DVI, and is overclocked with a great warranty, but the cards have been basically vaporware for the last 3-4 months. I just now saw one at bestbuy, and it was $250, not exactly a steal. Still, if you find one at a good price, go for it.
In terms of performance, I run HL2 at 1280x1024 with 4x AntiAliasing/8x Anisotropic Filtering, and get somewhere in the neighborhood of 35-45FPS. The AF isn't that important, but the AA makes a huge difference due to the large amounds of small, diagonal objects like fences and ledges and stuff. On a P4 with slower clock and memory (3.06 is a 533FSB, correct?) and no overclocking, I'd say you could get 40FPS at the same resolution if you turn off Anisotropic filtering, or dropping down to 2x AA. That's quite playable. On the other hand, a 9600 Pro would probably only be playable at 1024x768 with no eye candy.