Geforce 4 Ti4400 and it was fantastic. I remember back in the day you could buy a Nvidia GPU and it could still be decent after a few generations. Whereas today one generation behind Keplar can be total garbage compared to Maxwell in new games until it finally gets patched months later...
Back in the day I had an "in" with someone who had access to an Asus warehouse (legally!). and I got two two 6800 GTs, bios modded them, overclocked them, and water cooled them two weeks before they were released to the public - it was a good time!