Twin Kingdom Valley

I'm still enthralled by this game, but I think you might have to have played it in the early 1980s to appreciate it in the 21st century. Technically speaking, it's incredible to see what was achieved in just 32k of RAM (the Commodore 64 version was a port): a remarkably large map, an assortment of wandering NPCs with some degree of AI, and coloured pictures for most of the locations. But that's hardly the point - at least for those who were there at the time.