this was in the last thread,
sorry to say that it was all a
typo on the webpage and that there isn't going to be an x1800xl on AGP.
So that leaves either the x800 series or the 6800 series as the best available on AGP.
As for which is the best it all depends on who you talk too, personally I've got a 6800gt (which I am very happy with) but I've recomended x800's to friends also, mainly because the card is smaller (for systems without much room in them) and on the resolution's they are playing at, AA/AF can be used and ATI seems to hold its framerate better when dealing with AA.
Basically its the same old story, if you are playing OpenGL based games, then go Nvidia, if you are playing DirectX, then go Ati. Framerate differences are marginal at best.
The only difference that could play a part is the Shader Model, the 6800's can do SM3.0 where as the Ati cards can only do 2.0b, however in all real world gaming i've come across I can't tell the difference, neither can other people in most reviews I've read.
Possibly in a year or so with a few more games using SM3.0 it **might** become important, although by that time the x800 and 6800 series will be showing their age and most likely the system as a whole if it is using AGP, not that the games won't be playable, just trying to play new games with max settings probably won't be achievable and hence most of the pretty effects made available by SM3.0 won't be also...(not that SM3.0 enables any prettier effects, just allows them to be coded easier and run quicker).
Choose either the x800(gt/gto/xl/xt) or the 6800(gt/ultra) you won't go wrong with either, most telling difference is the price at the moment and on that front, with the old generation, Ati
seems to be winning in most cases with the x800gto which, (with a little work) is basically a x800xt, just for a lot less $$$/£££.