New bike is only one, in 1998: Peugeot Country 400 trekking with Shimano Altus-STX mix equipment.
To this day, this is my daily general working horse with some replacing parts.
Used bikes there were several. (But these are specialized shops for used bikes) :
Bianchi Vento 606 / Campa Veloce,
Pinarello Veneto Donna /shimano 105 (for my wife)
Bianchi Genius / DA 7402
Puch (Austro-Daimler) Superleicht/ Campa NR
Pinarello Montello/ shimano 6400
In private trade, I prefer to buy just frames, which I would like to fit with parts myself.