For me, it’s an electric toothbrush. It doesn’t matter if you go with Sonicare or Oral-B, once you start using an electric toothbrush, regular toothbrushes don’t ever feel like they clean your teeth properly. The smooth plaque-free top layer of your teeth that you can feel after using an electric toothbrush can’t be replicated with a regular toothbrush.
Electronic countertop scale for the kitchen. Start cooking by mass rather than trying to decide if that’s a half a cup packed or unpacked.
If you regularly store things in jars, a canning funnel. So much easier to pour sauces into jars without spillage.
Bone conduction headphones. Listen to music or talk on the phone hands-free while still leaving your ears open to what’s going on around you.
If you’ve got sore muscles, a percussive massage gun. It looks like a horse vibrator, but it does wonders on a sore back.
A warhammer. Don’t get a sword unless you are actually trained and know how to use and maintain it. A warhammer isn’t going to get bent, chipped, or rusty, and even if it does, it’s still a warhammer and will still smash things just fine. Don’t smash melons or coconuts unless you’re prepared for the biological mess that will get left behind; smash blocks of ice frozen inside of old yogurt tubs instead. Wear goggles.