There's always the odd exception and things vary a little from game to game BUT 4200 is clearly the superior card even at default and they o/c to at least 4400 speeds which is way better. Rad8500 is the next closest along with the GF3TI500, Rad8500LE is about 10% slower and then GF3TI200 is not too far away. Rad9000 is est to be about 20% slower than Rad9000PRO plus the PRO comes in the very worth while 128MB form much more readily. Rad9000PRO is slower than Rad8500LE and GF3TI200 in pretty much all benchmarks, still way faster than ALL GF4MX cards and all these other cards like Rad9000 sport DX8 hw unlike GF4MX. As for 'eye candy' the GF3 and GF4TI have HUGELY better AA, sure Radeon8500/9000 AA looks a little nicer but the perf hit makes it useless. As for Aniso Rad8500/9000 only take half the hit but GF3/GF4TI tend to look better, so that's pretty even.
Rad9000 vs GF4MX = Rad9000
Rad9000PRO vs Rad8500 = Rad8500
Rad8500 vs GF3 = Very equal
Rad8500 vs GF4TI4200 = 4200
However 3D perf isn't the be-all-and-end-all, GF3 cards suck for image quality and are lacking in every other dept. Both GF4TI and Rad8500/9000 offer HUGELY better image quality, dual display and TVout while the Rads also offer hw DVD playback. Clocks and features like dual display often differ with Rad8500 cards and Rad9000 cards (clocks only) with oem vs retail and also by manu, but nothing hugely significant. If you have a < $100 budget GF3 are good if 3D perf and AA are most important but Rad8500 or even Rad9000PRO are a much better all-round buy, in 128MB forms Rad8500 is not only faster but cheaper than Rad9000. If you have a fast CPU then GF4TI is a much smarter move and offers the best of both worlds with the added ability to increase perf with every mhz of CPU power.
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