The best reviews I've read on any of these, performance/cost ratio-wise
(value, IOW), is the Ti4200 AGP8x. A very solid performer, for not too much
$$$. If I recall the only downside is the lack of DX9.0 compliance. It may
sorta 'go out of style' in the not too distant future, but I bet you'll be
very happy with it for quite some time ...
Here's a couple good articles at Toms regarding some of the current video
cards. After much research (esp. into my budget) I opted for the Radeon
9500 Pro. The 9700's are definitely worth a look as well.
http://www6.tomshardware.com/graphic/20021024/ati-01.html
http://www6.tomshardware.com/graphic/20021202/radeon_9500-02.html
Once I got this ASUS a7n8x and some kick-ass memory, the 9500 Pro is singing
like a bird (an older Mobo (msi k7dmaster) with cheap memory was NOT
HAPPENING) these days. My (highly subjective) feeling is that the Nvidia
cards are a bit more forgiving in this department, so if all you can afford
is vid card and don't have new, higher end components to go with it, I'd
probably be thinking Nvidia. Just my $.02...