Memorial Day is upon us, but before you toast to the summer ahead, I have one request: Don’t sleep on the best Memorial Day mattress sales. Retailers are hosting sale events with markdowns on outdoor furniture and more seasonally appropriate gear, but it’s also the best time to save big on interior furniture —and most notably, the best-selling mattresses on the market. The holiday is technically on Monday, May 25, but I’ve already spotted several of the best Memorial Day mattress deals (some well over 50% off). Between spending roughly one-third of our lives in bed and the hefty price tag on most mattresses, these deals are well worth exploring. Plus, as a parent to a toddler, quality sleep has never been more important to me (or my Oura ring). That’s why I was eager to bring home the PlushBeds Botanical Bliss Organic Latex Mattress last year. To make sure you’re making a wise mattress purchase, I’m only highlighting deals on beds that are tested and beloved by AD editors and contributors.…