Really can't remember; a single-speed bike with 20" wheels is the first one I have a recollection of. I think the label on it was 'Triumph' but I can't even clearly remember the colour.
However, the first bike I actually bought turned out to be a bit of a classic. It was a second-hand Witcomb with 531 butted tubing, Campagnolo Nuovo Record rear derailleur and a simplex front derailleur, Campagnolo hubs and tubular wheels. It probably dated from the late fifties but was in quite nice condition. After a few years (1974, I think) the thread in the bottom bracket stripped so I went to Witcomb in Deptford, East London for help. We ummed and aahed for a bit and eventually I bought a new 531 frame tailor made to my size. I still have that frame now with the original Cinelli bars, although everything else has now changed. At some point around 2000 I decided I wanted it to be useful rather than a museum piece and had it adapted to take 700C wheels and modern parts and put an all-new Campagnolo Veloce groupset on it. Only two changes since then: the Veloce hubs couldn't take the daily grind so it now has Chorus hubs, and I swapped the chainset for a Stronglight compact one.