Polaris RZR is a very popular off-road vehicle, and there are many different coolers that can be used with it. The best cooler for Polaris RZR will depend on your specific needs and preferences. If you are looking for a cooler that can keep your food and drinks cold for long periods of time, then you should consider getting a Yeti cooler. If you are looking for a lighter weight option, then the Igloo Trailmate might be a good choice. Ultimately, the best cooler for Polaris RZR is the one that fits your individual needs the best.