I’ll go first
WaterPik water flosser- truly life changing, it takes a couple of days to master but once you do OMG you won’t believe how much better your teeth and gums look and the stuff that comes out of your mouth, far more effective than regular flossing. I use lukewarm water in mine before brushing.
Cold press Juicer- fantastic machines that make delicious drinks jam packed with vitamins. Great for someone who enjoys making things in the kitchen - definitely not for someone who wouldn’t enjoy the process.
Electric blanket- it still shocks me how many people don’t have one and hadn’t ever considered the idea of them- life changing!