Every Prime Day, I find myself surprised by the random categories that seem to be prominently featured. You always expect a headphone deal or some other discounted tech. But you might not anticipate seeing heavily discounted coolers. I’m the lead tester for our guide to the Best Coolers, which means my entire apartment would be completely overrun if I didn’t have my colleagues taking up space in their basements, garages, and camper vans to help me test them out. We’ve been testing our top picks for years and are always evaluating new options. Our old standbys and recent favorites are both on sale for Amazon Prime Day. Find our top picks below. Be sure to check our list of the Absolute Best Prime Day deals for more can’t-miss discounts, or come hang out at our live blog where we’re sharing real-time commentary and lots of bad jokes. Yeti Hopper Flip 18 for $225 ($75 off) Yeti Hopper Flip 18 Portable Soft Cooler Yeti’s rotomolded cooler deals keep going out of stock, but we still like …