The GeForce is the fastest, but has v high power requirements and issues with some mobos, the TNT2 Ultra is quite fast but agains some compatibility issues, The Voodoo (Plunx the Voodoos main selling point was 60fps capability in games) is the most compatible, has the most features (ie built in TV tuner and DVD decoder) but is only capable of 3D up to 16bit colour mode and probably slightly slower (except in games which support 3DFX Glide).
My train of thought is a runaway!!
AHHH, I think my computer's got a Virus!
Oh no, that's Windows XP
Chimaera: Twin Athlon MP 1900+ @ 1824Mhz, GeForce 3 TI500, 512Megs Crucial RegECC, 100GB Total HDD, SuSE Linux 7.3 + Windoze XP Pro