What is in your opinion the most impressive horological achievement/ complication

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Not looking at a specific brand but in general, what complication do you appreciate the most when talking about watches.

Let me give you my opinion about the 3 that will probably be the top 3

1/ minute repeater
Tbh it’s the most expensive but imo also the most useless. Never cared about it at all. And tbh I barely hear a difference between a mediocre and what should be a good one… and believe my I’ve seen most of them

2/ tourbillon
For others this is by far top notch in a watch.
And while I appreciate it I have 2 remarks. First it’s as good as useless in a wristwatch, only had a major positive impact in a pocket watch. Second …. Imo if you would buy you have to pay an insane amount cause the Chinese crap for 1 k and even tag heuer and chronoswiss at 15 k do not do it any justice.
Going for this grande complication you have to go all in and that means SUPER finishing. So think about AP, Breguet, patek, Girard Perregaux, Vacheron

3/ perpetual calendar
Well once it was probably useful but today we use our laptop, tablet ….
I know, this can be said about watches in general… who needs one anyway ?


So what is your dream (grand) complication…. And why ?