I remember collecting car registration numbers, at that time each town had it's own letter prefix before the number.
The interest was to spot a number that was from another area and then record it, for it's rarity.
I also remember collecting Bus tickets, the interesting ones were 'Worker's Returns', 'Exchange' tickets etc.
Also collected, American 'Fag Packets' ie Camel, Lucky Strike, Philip Morris etc. And also American chewing gum wrappers.
And dare I say it without some calling me a Neo-Nazi, I also collected Nazi badges.