I could never get rid of my Rocky Mountain Vertex.
This past year I've sold:
1997 Haro MX1 DH bike
1998 Specialized Rockhopper Nitanium (with Cook Bros. Cranks! *cry*)
Bianchi B.O.S.S. number 326 off the line (I still beat myself about the head and shoulders for selling it)
Haro Mary 29'er - rode it 4 times. No more 29'ers for me.
Kona Cindercone - was my "urban assault" bike with triple clamp fork, RF cranks w/bash guard, etc.
Trek 1000
Schwinn Collegiate 3 speed
1976 "Spirit of America" Stingray
I think that's about it. I might have missed one or two that I acquired and then sold immediately.