Nothing out there is going to be less maintenance if you want it to last. But that said, rotary cutters arent really high maintenance machines. Keep the oil topped up, the vent hole clear, blades sharpened once in awhile, and keep the deck clear of debris that rot them out. thats it.
But on to your question. Bushhog, landpride, woods, rhino, seem to be about the top 3.
But even lighter duty stuff like KK will last YEARS if you arent using it commercially and only cutting a few acres a few times a year. Others may disagree with that though. But I have had good luck with SEVERAL no-name or cheaper brands 5' cutters that are old and rusted and can be had on craigslist for under $200 everyday. Some of them look like they have been through the ringer, and still have tight gearboxes. Which is about the only thing that can be expensive to fix. Everything else can be welded and patched cheaply if you ahve a welder:thumbsup: