One of the most enduring british toy companies has to be Britains. Its outlasted Airfix, Meccano, Triang and most of the other big names. As far as im aware, its still producing quality toys today, although in a much reduced fashion. In the sixties, there were always Britains toys at home. My sisters had the Farm and Zoo sets which came down to me and later the Floral Garden sets, which they still cleave to in their fifties!
I was always bought the army sets by my dad, who kept my battalions up to scratch with each new release. He also ensured he got each new catalogue and leaflet, to keep for reference.
One of the more unusual additions to the Britains range was the Bandetta Elastic Band gun, a ridiculously simple hand gun that shot rubber bands with surprising accuracy and power. Basically a two piece mechanism of outer case and sliding ratchet inside, it was introduced in the 1969 catalogue and still appeared all the way up to 1973. It came carded with four little targets to cut out of the card. I'd dearly love to get my hands on one of these again!
Another big favourite of mine in later years was the Stargard series of spacemen and frogmen-like aliens. The gorgeous green alien ships with black accessories were a real triumph of toy design. They were later churned out in white with red and blue accents, looking more like the world cup in space than anything else!