The bikes I have that are in rideable condition all feature frames about which I was nostalgic, i.e. that I lusted after as a teenager but couldn't afford then.

I am nostalgic for Clement Criterium Seta tubular tires. Simply the best, and priced like it - they cost about as much as s decent radial car tire, back when bias-ply tires were still available and radials were decidedly high zoot. I am mildly nostalgic for the Bob Jackson I bought as my first big purchase from my first job out of high school. Bought the frame in 1974 or 1975 and built it up with the proverbial dog's breakfast of parts a teenager could afford or scrounge. It was stolen out of my garage c.1992. In both cases, I am not nostalgic enough to do anything about sourcing them.