[Jamo]

Breitlings are highly regarded for maintaining accuracy...at or near the top. Every model is COSC certified (less than 5% of all Swiss watches are). Their Professional Series are tools for airline and military pilots...they have to be dead on.

That is a good standard to use if you're going for any manual or automatic movement and you demand accuracy. Doesn't always have to be the most expensive brand/model either...some companies submit certain watches for certification, or use commercial movements which have already met certification requirements in other fitments, making them safe bets to get certified when they use them in one of their own models.

Now, some other things come into play, such as how you use your watch. A manual movement is excellent if you wear it every day and keep it wound. Some have a reserve complication to insure you never let it wind down completely. An automatic that is regularly worn or rotated on a winder will continue to be accurate...sitting around for extended periods is not a good thing.

Electronic watches are generally accurate, as are some other time measurement approaches. Accutrons (the tuning fork watch) were always damn good, and are being reintroduced. Citizen's Eco-Drive has earned high marks as well.