I feel like the odd man out, I bought most of my bikes new. Still in the household...

'80 Raleigh Record Ace, England/new (Queen Mother of the fleet.) One micro rebuild to accomodate a generator light and a new wheelset.
'89 Cannondale CR USA/used to see if I liked Cannondale frames. 4 1/2 builds since.
'96 Cannondale R400 USA/new bought specifically for the frame color. 3 builds so far.
'98 Trek 7000ZX USA/new Ordered based on an ad in Bicycling. Replaced fork, saddle and shifters, been a splendid choice for me.
'99 Cannondale CAAD3 frameset USA/new with 1 build plus minor tinkering.
'00(?) Santana Arriva SE USA/new now parting out as the kids are grown and gone, but still mostly here.

Kids builds are an old Olmo frameset for my son and a '90 Bianchi Volpe bought new (Japan or Taiwan) as NOS for my daughter and I converted to STI.

Fun times!

Brad