I work on quite a few different brands, so I've seen just about every end of the spectrum. There are some light duty "offshore" versions available at big box home stores, parts availability can be an issue with those, and I have seen some drivetrain problems, probably caused by folks overloading them, as they are not as robust as the name brand models.
Hands down, the best built one I have dealt with personally would have to be the Kubotas. Three cylinder diesels, integrated automatic transaxles, (vs. the belt drive used on a lot of models),a host of options and accessories, and just plain built to last. Very rugged.
Personally, I own an older Kawasaki Mule, and I love it. 2 cylinder liquid cooled,4WD, high/low range, and locking differentials... it is as surefooted as a mountain goat, and works hard for me whenever I need it. I have a 6' snow blade for the front for winter chores, and a winch for warm weather activities. (cutting firewood, pulling logs) I use it to remove and install my floating dock, and I built a custom boat trailer to haul my 2-man plastic boat back and forth to my ponds. Is it as heavy as the Kubota? No.
I would recommend sticking with a known brand, whatever you decide.
