Forget the GF6800XT it's kinda crap, if anything get the GF7600GS for AGP or you could try to wait for the GF7600GT. The GS with dual DVI is a little scarce in AGP form.
IMO your choices are the X1600 or the GF7600 series, and then it comes down to what else you plan on doing with them, and if gaming what games (although that's more for the GS vs PRO/XT debate rather than the GT which wins most situations in gaming).
But if you're doing video editing or something else then it makes a bit of a difference. So what apps/games you using it for?
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