I still have my circa-1973 AMF Roadmaster Scorcher orange 10-speed.
That old bike served me well back then; before I got my first car I rode that thing all over the towns where I went to school and work.
More recently, I rode it for about a year before getting my Trek. The back wheel has suffered some sort of damage over the years and won't quite true up, and the bottom bracket has a disconcerting amount of play in it, but it's still very ridable.
I plan to do some upgrades on it and keep it on the road. First thing on my agenda is to swap out the pedals (the last time I rode it, I about couldn't figure out how to pedal since it doesn't have clipless pedals), and replace that rear wheel.