Keep in mind that its worth EXACTLY what you pay for it AR ($25). Considering that you can get the new 5200 for like $60 or so and its fully DX9. Whereas the geforce 4 MX crap I dont think is even DX8 (shaders and stuff) since its based on geforce 2.
When I said DX8 and DX9 I'm talking about specific shaders and stuff, of course you can still run those versions of directx you just wont get the special features that they enable.
Personally I'm pretty happy with my geforce 4 4200 128 meg (fast memory) that I got for $100. The 4200 is still quite a lot faster than the new 5200.
All that said, I'm definately pro nvidia, if you want ATI they are fairly cheap too.