I have a cuckoo clock, but nowhere to mount it (so it lives in a box). I have an eight day pendulum clock hanging in the hall, which over the years I've calibrated fairly well (I need to add about twenty seconds every month-ish).
My mechanical watches are pretty good on the whole. My Sinn is losing, as I mentioned, but is doing so very consistently, and used to keep better time. It probably needs re-regulating, but I can't afford to do that right now. The watch in question is filled with inert gas as part of an anti-humidity system, so I can't just take it anywhere for a service.
My mechanical pocket watch runs a minute fast each day, but I don't wear it often; it's good enough for a night out.
My quartz gear keeps very good time; a couple of seconds in a month, although one Timex has a habit of speeding up when left in direct sunlight.
The radio controlled hardware I have in the house (watches and wall clock) keep excellent time, but hands down the best is my NTP server.
I'm a bit of a time nut. I like it when all my pieces (even the mechanicals) are within a second of each other, which they often are.
So, given an infinite budget, which watch would you all purchase?
Choice 1 (usually not for sale): http://richardmille.com/watch/rm-39-01/
Choice 2 (too much to justify right now): https://www.breitling.com/en/models/navitimer/navitimer-gmt/