This will get moved by a moderator, so onto the question at hand. Haven't used either, but a couple of my friends have XFX cards and think they're good aswell as a few magazines I've ready saying they're very fast . Doubt it would make all that much difference, but if I was picking, I would go XFX.
TBH unless you're getting a pre-overclocked one they are mostly all the same... Some might utilise faster memory than others, but the stock clocks are basically the same... Either of the above will be fine, jsut go for the cheaper option/best package...
I want SLI, and I want PCI-E. The price for the dual Chaintech 6600GT's is $380 ($190 X 2), a single EVGA 6800GT is $382. Not being an EVGA fan (bad experience with the 5900 Ultra and their sh!tty "customer service"), the next up in lowest prices is $390. The Asus GT is only $320, but it only has 128mb of RAM. The cards that I would settle for are past the $400 mark (the BFG for $419 and the Gigabyte for $459). I was able to buy my 6800GT Gigabyte for $405 (AGP). I try to only shop from 2 places unless there's something I NEED and Newegg or Zip Zoom Fly doesn't have it. My "value" SLI rig will probably include an Asus or Gigabyte Nforce 4 SLI board, a pair of Chaintech 6600GT's, a 160gb IDE hard drive, a Sony DVDROM/CDRW combo drive, 512mb of DDR400, a 90nm AMD64 chip (the 3000 or 3200 are looking good), onboard sound and LAN. It will be limited to a 1280 x 1024 resolution, so any video card higher than the 6800 basic is probably a waste.
My personal recommendation goes with the BFGTech 6600 GT OC - read about it here: http://bit-tech.net/review/387/ Another one worth considering is the XFX GeForce 6600 GT.
bfg cards are really good i got the 6800 gt oc card i like it i had the x800 pro the 6800 gt oc kicked its ass go bfg