The file
Tiny cars, about an inch long, sold in packs and lost under every couch in America. The playsets folded up into a briefcase or a toolbox, which was the second-best part.
The best part was the commercial: John Moschitta reading the entire pitch in about ten seconds, ending with "if it doesn't say Micro Machines, it's not the real thing." Everyone could do the impression, no one could do it as fast.
Sources: Wikipedia — Micro Machines