Quartz of course. You only need to change the battery after a couple of years but generally quartz watches can last decades without any additional service. And of course there are solar/kinetic powered quartz watches which don't even need a battery change. On the other hand Mechanical movements will need regular service but with cheap ones it's usually cheaper to replace the whole movement instead of having a watchmaker to service it. Usually the recommended service interval would be something like 5-7 years but of course the movement can last longer if you are lucky.
