Loving this thread.
First bike was a Raleigh Boxer. This was similar to the Strika which a few have mentioned above but slightly lighter iirc. Same metallic blue colour scheme as the popular (among larger boys who probably really wanted Choppers but their parents wouldn't let them!) Grifter.
The old man wasn't for letting me have stabilisers so I remember a few days of riding along with one or other parent holding onto the saddle, then falling off whenever I noticed they had let go.
After a year or so I got a little red 3-speed (derailleurs!) racer which was apparently a French import. Can't remember the brand. The Boxer was retained for pratting around with friends while the racer was only for longer family rides. For about 18mths or so we didn't run a car so that little racer covered a lot of miles around the lanes. We lived in a wee village about 6 miles out of Shrewsbury at the time.
Think I had a 5-speed Raleigh racer of some kind for a while then definitely a 10-speed Raleigh Winner followed by a 10-speed 531-framed Coventry Eagle tourer when I was about 14-ish. By that time we were living in Mid Wales and I had a group of mates that I used to ride a lot of miles with. Most of them had some sort of Raleigh racer except the lad whose cousin worked for Dawes and got him a 753-tubed beauty at an extremely low price. He's still got it somewhere I think.
Getting into the late '80s/turn of the '90s now and the mountain biking craze was really kicking off even in remote Wales. The tourer got taken up a few muddy mountain tracks (good thing I was lightweight back then - it would break if present-day me tried it!) unti I managed to save up cash from my couple of part-time jobs plus "Xmas money" and bought a "last years model" Specialized Hardrock Comp. Pre internet of course - I think I found it in an ad in the back of Bicycle Mag or something. Phoned the retailer and sent off a postal order. Still remember the excitement when the big box arrived and I couldn't wait to pull it out and assemble it. Indexed gears on the bars (thumbies) were a revelation.
Sold the Spesh and the Cov Eagle to help fund the purchase of a Lotus MTB. This was the most fun bike I have ever owned. Massive fat aluminium tubes, amazingly light, super fast and manoeuvrable. Got it for a song off the dad of a friend, who had decided to quit his job and go and do a degree course so was selling virtually everything he owned. Stupidly sold it a few years ago to buy something more practical (an old Dawes Horizon tourer). Barely a day passes that I don't regret it.
Since moving out of Edinburgh and from a flat to a house I've been building up my stable (serious n+1 sufferer). My main road bike is the 531-framed Peugeot racer my Dad bought new in 1979 and had been rusting unloved in his garage for many years. It's still a bit rusty but it's a lovely ride on days when nothing decides to break.
A few weeks back I was trawling EBay for local "pick up only" bike deals and spotted the exact same model of Specialized that I had way back when. £50 and it's pretty much mint - for a 24 year old bike anyway. Just back home from a morning getting filthy on the West Pennine Moors with a couple of mates - one of whom described the bike as "very pretty". It kind of is but I didn't think anyone else would think so...