The way I would look at this upgrade is this:
How long until I plan on upgrading my CPU/MB?
What is my budget?
If I will be upgrading CPU/MB in say <3 months.
Wait to buy video card until then, prices will continue to drop.
If upgrade will be 3+ months from now.
Go for the best price/performance I can get cheap. That way I can get the most out of the card now while wasting minimal money. If the product I buy now is powerful enough, I may be able to stretch the time until I buy a new video card until after I buy the motherboard, then I can get a even better video card at that time.
<< RazorWind, you could throw a GeForce 4 in there, but your system wouldn't do it justice. You need a card more in tune w/ the rest of your system. Check out this Visiontek 5632 GeForce 2 card from Newegg.com. I just put one in my second system (Soyo 440BX board, PII-350) and for $46 you can't go wrong. >>
That seems to be the best answer right now... Unbelievably, the GeForce2 GTS with 32MB is cheaper than even a GeForce2 MX400 with 32MB. But it is much faster. Plus $50 is a reasonable amount to spend on a video card for your system.
People may tell you that you will be CPU limited with this card. Who cares? You'll probably spend about the same for this card as a much lesser card. You'll get hardware T&L. And, when you get a faster CPU, the performance will improve. So even if you have a friend give you a 450Mhz cpu for your rig, you'll continue to see improvements.
Not to mention, there are still people running these cards with 1Ghz+ cpus and love them.
In other words, spend as little as you can to get the most performance you can.
Good luck!