I don't know why, but I find watch mechanics super fascinating.
Few favorites for people with spare time (and lots of money if one wants to buy these):
Tourbillon: a watch complication where the main mechanism is mounted on a rotating wheel so that gravity doesn't affect the watch in a single direction.
Spring drive: A very recent mechanism that produces a perfect sweeping motion of the seconds hand. It combines both mechanical power (no battery) with a quartz crystal in a super cool way.
Minute repeater: a mechanical way for a blind person to tell the time.
And for about $100, you can still buy a mechanical Seiko with a see-through caseback so you can watch everything in motion. A gateway drug for many... but also a fine stopping point because Seikos are wonderful machines in their own right.
(Although, Seiko is doing away with their most affordable mechanical models, all the newer ones are $200+)
Few favorites for people with spare time (and lots of money if one wants to buy these):
Tourbillon: a watch complication where the main mechanism is mounted on a rotating wheel so that gravity doesn't affect the watch in a single direction.
Spring drive: A very recent mechanism that produces a perfect sweeping motion of the seconds hand. It combines both mechanical power (no battery) with a quartz crystal in a super cool way.
Minute repeater: a mechanical way for a blind person to tell the time.