2019 Mule Pro FXT - it absolutely killed me to spend the money because I'm cheap, but it has been well worth the cost.
Biggest things about Kawasaki over the others (or at least Polaris) - warranty is standard 3 years with Kawi and you have the option of extending it, and the Mule Pro FXT has doors.
May not seem like a huge deal, but I had a Mule 610 before I upgraded and the doors are money. It's still an open cab, but the half doors keep you a million times cleaner than open cab without doors, and the Kawasaki doors are solid and part of the design whereas most of the other brands have aftermarket soft door options that are a royal PITA.
Drawback for Kawasaki over Polaris will be that the Kawasaki sits lower to the ground. I had the dealer install a 4" lift before I picked it up, but even with the lift it doesn't have the wheel clearance that Rangers have. I have 26" tires on my buggy, could go up to 28" tires without any additional mods. Some folks can run 29.5's, but they will rub on turns. That being said, I haven't had any issues (yet) with clearance on my 26's. Next set will be 28's though just because.
Plenty of power, I can convert from front and back seat (6 seater) to front seat only with a huge bed in no time flat, and to me the Kawasaki was just better built overall, runs quieter and a better value. Others may disagree, and that's cool. I had no experience personally wit Polaris but most of the folks I know that own Polaris seem to have issues with them early and sometimes often.
If you do look at new ones, figure out what the difference between models are and whether or not the cost delta is worth it. Mine is an FXT, which is the base model. The next model up has LED headlights, power ports in the back seat and better rims. Which is fine, but they wanted about $1800 more for about $300 in upgrades. I added LED headlights for $40, upgraded my rims on both my mud tires and summer tires for $275 total and the wiring for rear power ports is already installed - I can buy USB ports off of Amazon for about $15 if I wanted to.
