I always wanted to do this, and I'm interested to see what other people have had for video cards. I will start with my history.
1998 - 2006
AGP
Nvidia Riva TNT
Diamond Viper TNT2 Ultra
Creative Labs Geforce 2 GTS
OEM Geforce 3(non-ti)
Albatron Geforce 4 ti4200
Ati Radeon 9800 Pro 128mb
Ati Radeon 9800 Pro 256mb ->flashed to XT
Leadtek geforce 6800NU
Evga Geforce 6800GT ->oc'ed to Ultra
PCI-E
XFX Geforce 7800GT 256mb
Evga Geforce 7900GTO 512mb
1998 - 2006
AGP
Nvidia Riva TNT
Diamond Viper TNT2 Ultra
Creative Labs Geforce 2 GTS
OEM Geforce 3(non-ti)
Albatron Geforce 4 ti4200
Ati Radeon 9800 Pro 128mb
Ati Radeon 9800 Pro 256mb ->flashed to XT
Leadtek geforce 6800NU
Evga Geforce 6800GT ->oc'ed to Ultra
PCI-E
XFX Geforce 7800GT 256mb
Evga Geforce 7900GTO 512mb