3dmark has been marred by cheating, to the point that few reviewers still use it, but it is convenient - there are timetrial modes in a lot of ganme demo's - Aquamark is one that springs to mind.
3Dmark 2003 would be the one to go for on this class of card, and comparing Nvidia to Nvidia, the driver cheating doesn't matter.
A brief history of 3Dmark has some interesting pointers...
1. The 99/2000 era - tests were DX6, maybe even DX5
2. 2001 - 3 tests were DX7 (capable of running on DX6 hardware using software T&L), one required DX8
3. 2003 - 1 DX7 test, 2 DX8 tests, 1 DX9 test
The 2005 version (I'm not really keeping up on them), is likely to major in DX9 - and these tests DO echo the high end gaming of the period.
Basically though, the Geforce 4 Ti 4200 is the very creditable bottom level of what was probably Nvidia's finest range of cards (excluding the marketing con trick that was the 4 MX), but it's a DX8 card,
The 5700LE is a light/midrange DX9 card.
If you're looking back to DX7/DX8 game support, the Ti4200 is the stronger.
If you're looking forward to DX9 (beginning to become more important now), then the 5700LE is the only choice.
Between an adequate DX9 card, and an excellent DX8, I'd be inclined to go with the DX9 solution, as it looks forward, not back.