I’m a watch fan but I’m mostly ignorant of how progress was made from, say, the Antikythera mechanism to TokyoFlash. As one might expect, there are a ton of one-offs, ingenious ideas, and mechanical indulgences which signalized the advancement of the art of the timepiece. There’s a great list here of some of the most influential watches and watchmakers in history.
I personally find the earliest ones the most compelling, because I feel it was a more experimental time and probably there were some truly interesting solutions to various timekeeping problems. Later on I feel that the feature crunch and precision aspects took over, and although the Caliber 89 is an unbelievably awesome thing, I think the watch with the stretching and expanding hands (pictured on the left, above), is just such a fun idea.